Zephyr ZSI 100
The Zephyr ZSI 100 is a malleable penile prosthesis made by Zephyr Surgical Implants in Geneva, Switzerland, for men with erectile dysfunction who are candidates for penile implant surgery. It uses two silicone cylinders with an inner metal core, a bi-material central body combining silicone of different hardnesses, and a hydrophilic PVP coating intended to reduce infection risk. Its most distinctive practical feature is that the surgeon can shorten it from both the distal and proximal ends, giving a single device an adjustable length range from 25 cm down to 12 cm. ZSI is the only European manufacturer producing both malleable and inflatable penile implants alongside artificial urinary sphincters. The device is CE marked and is not available in the United States.
- Swiss-made, European alternative — Zephyr Surgical Implants is the only European manufacturer of malleable and inflatable penile implants and artificial urinary sphincters.
- Adjustable from both ends — The surgeon can reduce length from both the distal and proximal parts, covering 25 cm down to 12 cm from one device.
- Three diameters — 9 mm, 11 mm and 13 mm.
- Bi-material central body — Combines silicone of different hardness grades rather than using a single uniform silicone.
- Hydrophilic PVP coating — Intended to work against infection.
- A dedicated soft version exists — The ZSI 100 CF is offered both for erectile dysfunction and to hold corporal space against fibrosis while healing after a penile implant infection.
- Not available in the United States — ZSI is CE marked and ISO 13485 certified but is not currently seeking FDA approval.
- Published outcome data is the weak point — There is no published clinical outcome study for the standard ZSI 100. The available Zephyr malleable data relates to the separate ZSI 100 FTM device.
About the Zephyr ZSI 100
What Is the Zephyr ZSI 100?
The ZSI 100 is a malleable penile prosthesis designed to treat erectile dysfunction.
It is composed of two malleable cylinders implanted in the corpora cavernosa.
There is no pump, no reservoir and no hydraulic tubing.
The cylinders remain semi-rigid at all times, and the patient positions the penis manually for intercourse and afterwards for concealment.
It is manufactured by Zephyr Surgical Implants, based in Geneva, Switzerland.
Who Zephyr Surgical Implants Are
Zephyr occupies an unusual position in this market.
The company describes itself as the only European manufacturer of artificial urinary sphincters and of both malleable and inflatable penile implants, covering incontinence, erectile dysfunction and gender-affirming surgery.
Its product range includes the ZSI 100 malleable implant, the ZSI 475 three-piece inflatable implant, the ZSI 375 artificial urinary sphincter, and dedicated ZSI 100 FTM and ZSI 475 FTM devices for phalloplasty.
ZSI is ISO 13485 and CE certified.
For patients in Europe, the Middle East, Latin America and Australasia, Zephyr is a genuine alternative to the American manufacturers. For patients in the United States, it is not an option at all.
Cylinder Construction
The ZSI 100 uses two silicone cylinders with an inner metal core.
Zephyr specifies NuSil medical-grade silicone.
The metal core is what provides axial support, in the same way that the Coloplast Genesis uses a silver wire coil and the Boston Scientific Tactra uses a Nitinol core.
Verification note for the editor: sources conflict on the core material. Zephyr's own product catalogue describes a pure silver inner core. The 2023 state-of-the-art review of malleable prostheses instead describes a Nitinol nickel-titanium cable with a flexible distal part. Both descriptions are published. Confirm with current Zephyr instructions for use before stating either as fact, or describe it neutrally as an inner metal core. This matters clinically, because a nickel-containing alloy is relevant to patients with nickel sensitivity.
The Bi-Material Central Body
Zephyr's technical documentation describes a bi-material central body built from silicone at three different hardness grades: 65 Shore, 35 Shore and 20 Shore.
Shore hardness is a measure of how firm a material is.
Combining harder and softer silicone along the length of the implant allows different parts of the rod to behave differently: firmer where column strength is needed, softer where flexibility or comfort matters.
This is a different engineering approach from a uniform silicone body relying entirely on the metal core to determine behaviour, and it is conceptually similar to the segmented construction used by the Shah prosthesis.
Hydrophilic PVP Coating
The ZSI 100 carries a hydrophilic PVP coating, described by the manufacturer as working against infection.
PVP is polyvinylpyrrolidone, a hydrophilic polymer.
A hydrophilic coating is not the same thing as an embedded antibiotic.
Coloplast uses a hydrophilic approach on the Genesis and Titan; Rigicon uses HydroShield; Boston Scientific instead uses InhibiZone, which is an impregnated antibiotic combination.
A hydrophilic surface allows the surgeon to choose the solution the device is dipped in during preparation, rather than fixing that choice at manufacture.
Three Diameters
The ZSI 100 is available in three diameters: 9 mm, 11 mm and 13 mm.
This matches the Coloplast Genesis and Boston Scientific Tactra, both of which are commonly available in three diameters.
It is narrower than the Rigicon Rigi10, which currently offers six.
Three diameters is adequate for most anatomy. The practical consequence of a narrower range is less room to fine-tune the fit in unusual corporal dimensions.
Adjustable From Both Ends
This is the ZSI 100's most distinctive practical feature.
Zephyr states that the surgeon can reduce the length from both the distal part and the proximal part, giving an adjustable range from 25 cm down to 12 cm.
Most malleable implants are supplied at a fixed length and adjusted proximally, with rear-tip extenders added to fine-tune the fit upward.
The ZSI approach works in the opposite direction: start long, trim to fit from either end.
The practical benefit is inventory. One device covers a very wide anatomical range, which matters for hospitals and for surgeons operating in centres that cannot hold deep stock of every size.
How the ZSI 100 Works
The implant is continuously semi-rigid.
When intercourse is desired, the patient manually positions the penis upward or outward.
Afterwards, the penis is bent downward toward the body for concealment.
The device bypasses the natural vascular erectile mechanism entirely.
No medication, injection or pumping is required before intercourse.
The ZSI 100 CF Soft Version
Zephyr also produces a soft version of the device, catalogued as ZSI 100 D9 CF, D11 CF and D13 CF.
The manufacturer describes two purposes for it: treating erectile dysfunction, and keeping corporal space free from fibrosis while healing after a penile implant infection.
That second purpose is worth understanding, because it is a distinct surgical role.
When an infected implant is removed, the corpora begin to scar down. Dense fibrosis can make later reimplantation extremely difficult or impossible.
A soft device left in place holds the corporal space open during healing so that a definitive implant can be placed later.
Not every manufacturer offers a purpose-made product for this. It is a meaningful point of difference for surgeons doing complex salvage work.
Published Clinical Evidence
This section needs to be honest, because it is where the ZSI 100 is weakest.
There is no published clinical outcome study for the standard ZSI 100.
The 2023 state-of-the-art review of the six major commercial malleable prostheses assessed the Zephyr malleable rods and found no published clinical outcome data for them, in contrast to the Genesis, Tactra and Rigi10, each of which has device-specific published series.
The device is CE marked and ISO 13485 certified, which means it has satisfied European regulatory requirements for safety and performance. That is a real standard, and it is not the same thing as published independent clinical outcomes.
Any source presenting confident survival, satisfaction or revision figures for the standard ZSI 100 is either extrapolating from other devices or quoting FTM data that does not apply.
Why FTM Data Does Not Transfer
Published Zephyr malleable outcome data exists, but it relates to the ZSI 100 FTM, which is a different device implanted in a different anatomy.
The FTM is a single-cylinder implant with a wide glans-shaped distal cap and a plate that fixes to the pubic bone. The standard ZSI 100 is a paired-cylinder implant placed inside the corpora cavernosa.
The surgical anatomy is completely different. A neophallus has no tunica albuginea and no corpora, so the failure modes, fixation problems and erosion risks are not comparable.
Applying FTM complication rates to a cis male ZSI 100 implant would be misleading, and the reverse is equally true.
The FTM data is summarised below purely so readers understand what it is and why it is separate.
What the ZSI 100 FTM Data Shows
The first study of the ZSI 100 FTM was a retrospective review across three European gender surgery centres in Amsterdam, Stockholm and Reykjavik, covering 25 patients with a mean age of 36 and a mean follow-up of 6.3 months.
Its authors concluded that complication rates seemed high at the start of the learning curve, and that not all patients would be eligible for this type of prosthesis.
A 36% explantation rate within the first six months has been reported for that cohort.
Patient satisfaction in the same group was high, with around 93% reporting they were satisfied or very satisfied.
A later retrospective cohort of 50 transgender patients undergoing 85 implantation procedures between 2017 and 2024 reported an 11% infection rate for malleable implants against 15% for hydraulic, and a late complication rate covering dysfunction, malposition and erosion of 58% for malleable against 56% for hydraulic, over a median follow-up of about 32 months.
These are phalloplasty figures. They belong on a phalloplasty page, not in a cis male's decision about a malleable implant.
ZSI 100 vs Coloplast Genesis
Both are malleable prostheses with hydrophilic surface technology and three diameters.
Genesis uses a silver wire coil or helix core; the ZSI 100 uses an inner metal core with a bi-material silicone body.
Genesis has published clinical outcome data. The ZSI 100 does not.
Genesis is available in the United States. The ZSI 100 is not.
ZSI 100 vs Boston Scientific Tactra
Both are contemporary malleable implants available in three diameters.
Tactra uses a Nitinol nickel-titanium core within dual-layer silicone and carries no antibiotic or hydrophilic coating on the malleable device.
The ZSI 100 uses a PVP hydrophilic coating.
Tactra has published device-specific outcome data and US regulatory clearance. The ZSI 100 has neither.
The ZSI 100's advantage over both American devices is its dual-ended trimming range.
ZSI 100 vs Rigicon Rigi10
Rigi10 offers six diameters against the ZSI 100's three, and has the strongest early evidence base of any current malleable device, with roughly 99.2% freedom from revision at three years in a 605-patient multinational study.
Both use a hydrophilic rather than an impregnated antibiotic surface.
On published evidence, Rigi10 is clearly ahead. On availability, the two overlap in many non-US markets.
ZSI 100 vs Promedon TUBE
Both are malleable implants marketed primarily outside the United States.
The TUBE uses a flexible silicone elastomer with a soft distal part, a medium-hardness middle section and a high-hardness proximal section with a silver core wire, and is offered in five diameters from 9 mm to 13 mm with lengths from 20 cm to 26 cm.
The design philosophies are similar: both vary material hardness along the length of the rod.
The TUBE offers more diameter and length combinations; the ZSI 100 offers a single device trimmable across a wider range.
ZSI 100 vs the ZSI 475 Inflatable
Zephyr's own inflatable device, the ZSI 475, is a three-piece implant with cylinders, a scrotal pump and a reservoir.
The trade-off is the standard one across all implant types.
The ZSI 100 is mechanically simpler, has no hydraulic components that can fail, and is easier to operate.
The ZSI 475 offers better concealability and a more natural transition between soft and rigid states.
For a patient already committed to Zephyr as a manufacturer, this is the real decision.
ZSI 100 vs Inflatable Implants Generally
The ZSI 100 is always semi-rigid.
An inflatable prosthesis moves between a comparatively soft resting state and a rigid inflated state.
The malleable device is simpler to use and eliminates pump, reservoir and tubing failures entirely.
The inflatable device conceals better and feels more natural at rest.
Neither is universally superior. The choice depends on dexterity, anatomy, prior surgery, cost and what the patient values most.
No Pump
The ZSI 100 requires no scrotal inflation pump.
This is particularly relevant for men with arthritis, neurological impairment or reduced grip strength.
The patient must still be able to reposition the penis manually.
No Reservoir
There is no abdominal or pelvic reservoir.
This simplifies the surgical anatomy and removes reservoir-specific complications entirely.
It can be relevant in men with extensive prior pelvic surgery, where reservoir placement is more difficult.
ZSI 100 and Corporal Fibrosis
Malleable implants are useful when corporal fibrosis makes hydraulic implant placement difficult.
The ZSI 100's 9 mm diameter allows a narrow rod to be selected where corporal space is restricted.
Severe fibrosis may still require specialised dilation or reconstructive techniques.
The existence of the CF soft version gives surgeons an additional option in this setting.
ZSI 100 in Salvage After Infection
Malleable prostheses have an established role in salvage strategies after infected implants, preserving corporal space while reducing hydraulic complexity.
Zephyr's decision to market a device explicitly for maintaining corporal space during healing after infection reflects this role.
Whether it is the right choice in any individual case depends on the organism, the tissue condition and the surgeon's salvage protocol.
ZSI 100 After Radical Prostatectomy
Men with severe erectile dysfunction after radical prostatectomy may be candidates.
The implant provides rigidity mechanically and does not depend on recovery of the cavernous nerves.
The absence of a pelvic reservoir can also simplify surgery after extensive pelvic dissection.
ZSI 100 and Diabetes
Men with treatment-resistant diabetes-related erectile dysfunction may be candidates for a malleable implant.
The device bypasses the vascular and neurological mechanisms required for a natural erection.
Poorly controlled diabetes increases infection risk, and medical optimisation before surgery remains important.
ZSI 100 and Peyronie's Disease
Malleable prostheses can be considered in selected men with both severe erectile dysfunction and Peyronie's disease.
Significant curvature may require additional straightening procedures.
Inflatable implants are more extensively studied in complex Peyronie's reconstruction, so device selection should be individualised.
Concealability
The ZSI 100 can be bent downward for concealment.
The penis nonetheless remains semi-rigid and does not become truly flaccid.
Zephyr does not publish a specific bending angle for the standard ZSI 100, and the 2023 comparative review lists its bending angle as unknown, in contrast to the TUBE at 130 degrees and the Rigi10 at approximately 135 degrees.
If concealment is a patient's highest priority, an inflatable device is the better answer.
Does the ZSI 100 Increase Penile Length?
No.
It is not a lengthening device.
The implant is trimmed down to match the patient's measured corporal anatomy, not sized to extend it.
Does the ZSI 100 Increase Penile Girth?
The three available diameters allow the surgeon to select a rod matching corporal width.
The chosen implant may affect postoperative shaft fullness, but this is not a cosmetic girth procedure and no specific circumference increase should be guaranteed.
Does the ZSI 100 Restore a Natural Erection?
No.
It creates mechanical rigidity.
It does not restore arterial filling, veno-occlusion or cavernous nerve function.
It does not directly affect libido, penile sensation, orgasm or ejaculation, which usually remain as they were before surgery.
Revision or Conversion
The ZSI 100 can be surgically removed or replaced.
Conversion to an inflatable device is possible later if anatomy and circumstances permit.
Revision becomes more complex over time as corporal scar tissue develops around implanted rods.
MRI Status
Flag for verification before publishing. No Zephyr MRI conditions statement for the ZSI 100 could be located, and the device contains a metal core whose composition is itself disputed between sources.
Recommended page wording: patients should provide their implant details to radiology personnel before any MRI, and the implanting centre should be asked for the manufacturer's current MRI conditions.
Do not label the device MR Conditional or MR Safe without a document from Zephyr.
Regulatory Status and Availability
The ZSI 100 is CE marked, and Zephyr is ISO 13485 certified.
Zephyr penile implants are not available in the United States, and the company is not currently seeking FDA approval.
Availability has been described as covering Australia, New Zealand and a number of countries in Europe and South America.
For patients travelling for treatment, this is the practical point: if you are being offered a ZSI 100, you are being treated outside the United States, and the device will not be serviceable by a US implant centre afterwards.
Warranty
Flag for verification before publishing. No Zephyr warranty terms for the ZSI 100 could be confirmed.
Do not state or imply a lifetime replacement warranty. Obtain the current warranty document from Zephyr or the implanting centre and reproduce its terms, including which country's law applies.
Is this device for you?
- •Patients outside the United States where Zephyr devices are distributed and American manufacturers may be less accessible.
- •Severe treatment-resistant erectile dysfunction when penile prosthesis surgery is indicated.
- •Patients with limited manual dexterity who would struggle to operate an inflatable pump.
- •Patients wanting simple mechanical operation without pump, tubing or reservoir.
- •Selected corporal fibrosis cases where a narrow malleable rod is appropriate.
- •Selected salvage cases after implant infection, where the CF soft version can hold corporal space during healing.
- •Centres with limited inventory that benefit from one trimmable device covering a wide length range.
- •No published clinical outcome data — The most significant limitation, and the main reason to prefer a device with a published evidence base if one is available.
- •Not available in the United States — And ZSI is not currently seeking FDA approval.
- •Continuously semi-rigid — The penis does not become truly flaccid.
- •Less concealability than an inflatable implant — And no published bending angle to compare against competitors.
- •Three diameters only — Fewer fitting options than the six offered by the Rigi10.
- •Core material unclear from public sources — Relevant to patients with nickel sensitivity; confirm before surgery.
- •No confirmed MRI conditions statement — Verify with the manufacturer.
- •No confirmed warranty terms — Verify with the manufacturer or implanting centre.
- •Not designed for penile lengthening or girth enhancement — Sized to anatomy.
- •Infection and erosion remain possible — As with any malleable implant maintaining continuous corporal pressure.
How it compares
Every malleable (semi-rigid) implant a surgeon in our network may propose, side by side. The Zephyr ZSI 100 column is highlighted.
| Attribute | Zephyr ZSI 100Zephyr Surgical Implants (ZSI)Economy | Tactra™ Boston ScientificPremium | Coloplast Genesis®ColoplastEconomy | Rigicon Rigi10™Rigicon Mid-range |
|---|---|---|---|---|
| Expansion | None — fixed-diameter malleable rods | None — fixed-diameter malleable cylinders | None — fixed-diameter malleable cylinders | None — fixed-diameter malleable rods |
| Rigidity | Permanent semi-rigid axial support from an inner metal core within a bi-material silicone body | Permanent semi-rigid axial support from Nitinol core | Permanent semi-rigid axial support from silver wire coil / helix core | Permanent semi-rigid axial support from stainless-steel core with titanium reinforcement |
| Antibiotic coating | Hydrophilic PVP coating stated by the manufacturer to work against infection; not a fixed embedded antibiotic combination | No fixed antimicrobial coating claim verified in current manufacturer product information | HydroVANTAGE™ hydrophilic coating; absorbs surgeon-selected aqueous solution rather than containing fixed embedded antibiotics | HydroShield™ hydrophilic coating; absorbs surgeon-selected dipping solution rather than containing fixed embedded antibiotics |
| Reservoir | None | None | None | None |
| Control | Manual positioning by bending the penis | Manual positioning by bending the penis | Manual positioning by bending the penis | Manual positioning by bending the penis |
| Concealed when soft | Partially — the implant remains semi-rigid; no published bending angle | Partially — bends downward for concealment but does not become truly flaccid | Partially — bends downward and resists spring-back but does not become truly flaccid | Partially — up to approximately 135° bending with limited spring-back, but the implant remains semi-rigid |
| Cylinder material | NuSil medical-grade silicone with an inner metal core; bi-material central body at 65, 35 and 20 Shore | Dual-layer silicone surrounding a Nitinol core | Flexible silicone elastomer with internal silver wire coil / helix core | Silicone-covered flexible rod with stainless-steel core and titanium-reinforced caps |
| Cylinder options | Diameters 9 mm, 11 mm and 13 mm | 9.5 mm × 14–23 , cm 11 mm × 16–25 cm , 13 mm × 18–27 cm | 9.5 mm × 14–23 cm 11 mm × 16–25 cm 13 mm × 18–27 cm | 9 mm × 23 cm 10 mm × 23 cm 11 mm × 25 cm 12 mm × 25 cm 13 mm × 25 cm 14 mm × 25 cm |
| Length expansion | None — length is reduced by trimming to match corporal anatomy | None — cylinders are trimmed to anatomical length | None — trimmable cylinders are sized to corporal anatomy | None — rod length is adjusted to corporal anatomy using sizing and extenders |
| MRI status | Not verified — no manufacturer statement located; confirm before publishing | MR Conditional under manufacturer-specified conditions | Verify current model-specific Coloplast documentation before publishing a formal MRI classification | MR Conditional at 1.5T and 3.0T under manufacturer-specified conditions |
| Reliability | 90–95% at 5 yrs* | 90–95% at 5 yrs* | 90–95% at 5 yrs* | 90–95% at 5 yrs* |
*Type-level five-year mechanical survival from published series; not a model-specific figure. See each model page for detail.
At a glance
- Manufacturer
- Zephyr Surgical Implants (ZSI)
- Type
- Malleable (semi-rigid) implant
- Price tier
- Economy
- Regulatory
- CE Mark
- Warranty
- Warranty terms for the Zephyr ZSI 100 should be confirmed directly with Zephyr Surgical Implants or the implanting centre before surgery, including what the warranty covers, whether it applies to the original patient only, and which country's law governs it. Warranty cover for penile prostheses is generally limited to device replacement and does not extend to surgical, hospital, physician, removal or reimplantation costs.
- Malleable / semi-rigid design — Two cylinders, permanent structural support, no hydraulic components.
- Inner metal core — Provides axial rigidity. Core material disputed between sources; verify before publishing.
- Bi-material central body — Silicone at 65, 35 and 20 Shore hardness combined along the rod.
- Hydrophilic PVP coating — Manufacturer states it works against infection.
- Three diameters — 9 mm, 11 mm and 13 mm.
- Trimmable from both ends — Adjustable from 25 cm down to 12 cm from a single device.
- Soft CF version available — For erectile dysfunction and for maintaining corporal space after implant infection.
- NuSil medical-grade silicone — Specified by the manufacturer for long-term durability.
- CE marked, ISO 13485 certified — Not available in the United States.
Surgeons who implant it
Surgeons in our network who work with the Zephyr ZSI 100. Availability of a specific model is always confirmed in your proposal.
Common questions
Is the ZSI 100 an inflatable penile implant?
Who makes the ZSI 100?
Is the ZSI 100 available in the United States?
Where is the ZSI 100 available?
What sizes does the ZSI 100 come in?
Why does trimming from both ends matter?
What is the ZSI 100 made of?
Does the ZSI 100 contain nickel?
What coating does the ZSI 100 use?
What is the ZSI 100 CF?
How reliable is the ZSI 100?
I have seen ZSI 100 complication rates quoted. Are they valid?
Is the ZSI 100 better than the Rigi10?
Is the ZSI 100 better than the Genesis or Tactra?
Is the ZSI 100 easier to use than an inflatable implant?
Does the ZSI 100 increase penile length or girth?
Can the ZSI 100 later be changed to an inflatable implant?
Can patients with a ZSI 100 have an MRI?
Does the ZSI 100 have a warranty?
Patient reviews
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- Zephyr Surgical Implants — Product Catalogue (ZSI 100 and ZSI 100 CF specifications)
- Zephyr ZSI 100 Malleable Penile Prosthesis — product listing
- Zephyr Surgical Implants — company and product overview
- Chung & Wang — State-of-art review of current malleable penile prosthesis devices in the commercial market (PubMed)
- Chung & Wang — State-of-art review, full text
- Contemporary malleable penile prostheses — full review
- Pigot et al. — Surgical Experience and Outcomes of Implantation of the ZSI 100 FtM Malleable Penile Implant in Transgender Men After Phalloplasty (J Sex Med 2020)
- Levy et al. — Hydraulic and malleable female-to-male penile implants after phalloplasty: a retrospective cohort analysis (BJU Int)
- An update on penile prostheses: a narrative review (Asian Journal of Andrology)
- Current devices, outcomes, and pain management considerations in penile implant surgery — PMC
- EAU Guidelines — Management of Erectile Dysfunction
- AUA — Erectile Dysfunction Guideline
- Zephyr Surgical Implants (ZSI) — product information