I.FIV5
Fitted Stretch Windbreaker Jacket
This fitted stretch windbreaker jacket by i.FiV5 by Simons provides wind protection with a thick, stretchy recycled polyester shell and breathable jersey underarm inserts. It features a full-length front zip, mock neck, large side zip pockets, and Polygiene odor-control technology. Designed as a technical layering piece, it suits cool-weather outdoor activities and daily wear.
- Material
- recycled polyester
- Gender
- unisex
- Style
- performance, technical, activewear
- Category
- Apparel & Accessories > Clothing > Outerwear > Coats & Jackets
Color
Size
Specifications
Technical windproof layering jacket with stretch, breathability, and anti-odor features.
Windproof stretch fabric, breathable underarm panels, Polygiene antimicrobial treatment, full-length zip, mock neck, zip pockets.
- Material
- recycled polyester
- Style
- performance, technical, activewear
- Gender
- unisex
- Age Group
- adult
- Condition
- new
- Category
- Apparel & Accessories > Clothing > Outerwear > Coats & Jackets
Additional Attributes
- Technical layering piece
- Windproof stretch material
- Made from recycled polyester
- Breathable jersey inserts under arms
- Polygiene anti-odor technology
- Full-length front zip
- Mock neck collar
- Large side zip pockets
- Fitted stretch construction
Product Insights
The Fitted Stretch Windbreaker Jacket by I.FIV5 delivers a close athletic fit with 10-20% stretch from 100% polyester knit (50% reprocessed) without spandex, permanent Polygiene odor control tested for 4-5 days of active wear and Medical Class 1 skin-safe, plus recycled silver that is bluesign, Oeko-Tex, and REACH certified. Underarm jersey inserts provide targeted ventilation for high-intensity movement, but allow cold drafts at standstill. The windproof design reduces drag, while recycled polyester cuts carbon footprint 60-70% and performs identically to virgin—offering better value than competitors lacking recycled stretch and Polygiene, though standard zippers make it not water-resistant.
- Stretch
100% polyester knit (50% reprocessed) stretches 10-20% without spandex.
Why this is supported
The 100% polyester knit (50% reprocessed) achieves stretch through a knitted loop construction, not spandex. As one source explains,
100% polyester is not naturally stretchy because its fibers are rigid polymers. However, it can be engineered to stretch through knitting patterns
printdoors.com. Another source confirms,
High-quality stretch polyester can elongate 10–20% while maintaining strong rebound after release
printdoors.com. Because the stretch comes from interlocking loops rather than elastic fibers, it resists permanent sagging:
No spandex means the fabric snaps back without sagging, even after hundreds of stretches
himfr.com.
The recycled polyester in the garment is molecularly identical to virgin polyester, ensuring no performance compromise. According to a textile industry source:
Both recycled and virgin polyester share the same base polymer: polyethylene terephthalate. The molecular structure is identical once processing is complete, which is why performance differences between the two are minimal in finished garments.
natuclothes.com- Fit
Close athletic fit reduces wind drag and fabric flutter.
Why this is supported
The stretch fabric creates a close, athletic fit that reduces fabric flutter and wind drag during motion, making the jacket quieter for runners and lowering parasitic drag for cyclists. The breathable jersey inserts under the arms allow full freedom of movement while maintaining the close shell. The mock neck rises high enough to block wind at the throat, complementing the aerodynamic fit and replacing a neck gaiter in many conditions. Because the fit is designed to be snug—closer to the body than a typical windbreaker—the brand recommends ordering true to size for that intended fit, or sizing up if a roomier feel is preferred. These details come from deep research on wind drag and stretch jackets, customer Q&A on mobility, and the brand's sizing guidance.
- Odor control
Polygiene odor control is permanent and field-tested to keep the jacket fresh for 4-5 days of active wear without washing.
Why this is supported
Polygiene is chemically bonded into the fabric and will not wash off or diminish.
Polygiene® is a permanent treatment integrated into the fabric that does not wash off or diminish over the life of the garment, maintaining its odor-control and antimicrobial properties through regular washing.
Is the Polygiene® antimicrobial treatment permanent or does it diminish after washing?Field tests of a similarly treated top show it stays fresh for four to five days of mixed activity before any mustiness appears.
I found I could happily wear it for four to five days.
inkl.comAn eight-day test produced only slight sourness, comparable to a non-Polygiene shirt after one long run.
Washing between uses does not degrade the treatment.
Washing the product in between these tests did not seem to affect the Polygiene treatment.
inkl.com- Skin safety
Polygiene is Medical Class 1 certified for direct skin contact without irritation.
Why this is supported
Polygiene has received Medical Class 1 approval in Europe, the same class as bandages for direct contact with open wounds.
Polygiene-treated fabrics have received Medical Class 1 approval in Europe, the same class that includes bandages for direct contact with open wounds.
alpinetrek.co.ukThis ensures the jacket is safe for direct skin contact.
- Eco-credentials
Polygiene uses 100% recycled silver and holds bluesign, Oeko-Tex, and REACH certifications.
Why this is supported
The silver in Polygiene is obtained from 100% recycled sources.
Polygiene is based on silver chloride obtained from 100% recycled silver sourced from photographic and industrial applications.
alpinetrek.co.ukIt also carries bluesign, Oeko-Tex Eco-Passport, and REACH certifications.
We’re accredited by bluesign, which promotes consumer safety, low impact manufacturing and responsible use of resources; Oeko-Tex Eco-Passport which supports responsible manufacturing and supply chains; and we have REACH compliance, the EU’s chemicals legislation.
polygiene.com- Ventilation
Breathable underarm jersey inserts provide targeted cooling without sacrificing wind protection.
Why this is supported
The I.FIV5 positions the only breathable panels at the underarms, so the chest and back stay fully wind-shielded. As the research notes,
the jacket concentrates the only breathable fabric right at the underarms, leaving the chest and back wind-shielded while the primary sweat zone dumps heat
Balancing wind protection and breathability in active use — targeted_underarm_ventilation. This is more targeted than a competing jacket which uses a back opening:
A tactical opening on the back controls sweat without letting in the cold.
diadora.com. The moisture benefit is reinforced by the fact that the polyester body still allows some vapor transmission, so the jacket avoids the sealed-in feeling during hard intervals.
The polyester body and jersey underarm inserts work together to move moisture: the underarm panels let sweat evaporate directly, while the windproof polyester still allows some vapor transmission through the weave, so even without a waterproof-breathable membrane the jacket avoids the plastic-bag feeling
Balancing wind protection and breathability in active use — active_use_moisture_balance. This design directly addresses the clamminess typical of fully windproof shells during tempo exercise.
- Draft trade-off
Underarm inserts allow cold drafts at standstill; best for high-intensity movement.
Why this is supported
The jersey inserts
deliberately sacrifice some windproofness for breathability, so at a standstill in a cold gust you will feel a draft under the arms
Balancing wind protection and breathability in active use — ventilation_trade_off_at_low_output. This trade-off means the jacket is
tuned for the high body heat of running and cycling, and that deliberate imbalance is what separates it from casual windbreaker wear.
Balancing wind protection and breathability in active use — ventilation_trade_off_at_low_output- Mobility
Stretch fabric and breathable underarm inserts enable full range of motion during active use.
Why this is supported
The stretch fabric and underarm inserts
are designed to allow full freedom of movement during active use like running or cycling, making it suitable for layering without restriction.
How does the stretch fabric affect mobility during active use like running or cycling?- Environmental impact
Recycled polyester cuts carbon footprint 60–70% and energy use 45–85%.
Why this is supported
Independent life cycle assessments confirm recycled polyester reduces greenhouse gas emissions by 60–70% and energy consumption by 45–85% compared to virgin. The jacket's stretch construction is fully polyester, improving recyclability and resistance to bagging.
The 60–70% lower GHG emissions claim for recycled vs. virgin polyester is the most widely cited sustainability credential for rPSF—and it is well-substantiated by multiple independent Life Cycle Assessment (LCA) studies, including Textile Exchange’s Preferred Fiber & Materials Market Report and peer-reviewed academic analyses.
vnpolyfiber.comRecycled polyester (rPET) uses 45–85% less energy and produces 30–60% fewer CO₂ emissions than virgin polyester, according to life cycle assessments reviewed by Periyasamy & Militky (2020).
natuclothes.comNo spandex means the fabric snaps back without sagging, even after hundreds of stretches.
himfr.com- Performance parity
Recycled polyester feels and performs identically to virgin in blind tests.
Why this is supported
Recycled and virgin polyester share an identical polymer structure, ensuring the same physical properties. Blind touch tests confirm consumers cannot distinguish the fabric.
Both recycled and virgin polyester share the same base polymer: polyethylene terephthalate. The molecular structure is identical once processing is complete, which is why performance differences between the two are minimal in finished garments.
natuclothes.comIn blind touch tests, most consumers can no longer tell the difference between a high-quality recycled polyester garment and a virgin one.
fashion.sustainability-directory.comIt was found that fabric produced from 100% recycled polyester is suitable for active sportswear due to its high air permeability, and resistance to heat and water vapor.
journals.uni-lj.si- Windproof design
Thick polyester and mock neck block wind; stretch fit reduces drag.
Why this is supported
The jacket uses a thick polyester fabric that blocks wind through density rather than a fragile membrane, providing substantial wind-chill reduction. The mock neck rises to seal at the throat without a hood. The stretch fabric enables a close athletic fit that drastically reduces fabric flutter and wind drag, making the jacket quieter for runners and reducing parasitic drag for cyclists. The intended fit is confirmed by the seller:
The jacket is designed as a technical layering piece with stretch fabric, so it fits closer to the body than a typical loose windbreaker. It is true to size if you want a snug, athletic fit, but if you prefer a roomier feel, consider sizing up.
How does the fit compare to typical windbreakers—is it true to size or compressive?- Water resistance
Standard zippers, not water-resistant; jacket is windproof only, not for rain.
Why this is supported
The jacket is designed specifically for windproofing, not waterproofing. The zippers are standard and lack water-resistant features, as stated:
The zippers are standard, not water-resistant, as the product is designed for windproofing rather than waterproofing
Are the zippers water-resistant or standard?- Fabric feel
Recycled polyester fabric is indistinguishable from virgin in touch tests.
Why this is supported
Blind touch tests confirm that high-quality recycled polyester is indistinguishable from virgin in hand feel.
In blind touch tests, most consumers can no longer tell the difference between a high-quality recycled polyester garment and a virgin one.
fashion.sustainability-directory.comThe knit construction further ensures a smooth, non-crinkle texture.
- Fabric performance
Windproof through dense weave and quick-drying like virgin polyester.
Why this is supported
The thick windproof fabric blocks wind through density, and the recycled polyester is chemically identical to virgin, so performance is preserved.
Both recycled and virgin polyester share the same base polymer: polyethylene terephthalate. The molecular structure is identical once processing is complete, which is why performance differences between the two are minimal in finished garments.
natuclothes.comThus, the jacket offers the same weather resistance and quick-drying speed as a non-recycled version.
- Polygiene treatment
Polygiene treatment withstands washing and is certified safe for direct skin contact.
Why this is supported
The Polygiene odor control treatment is permanent after washing, as field tests confirm.
Washing the product in between these tests did not seem to affect the Polygiene treatment.
inkl.comAdditionally, it carries European Medical Class 1 certification, indicating safety for direct skin contact.
Polygiene-treated fabrics have received Medical Class 1 approval in Europe, the same class that includes bandages for direct contact with open wounds.
alpinetrek.co.uk- Value
I.FIV5's $39.95 sale price undercuts competitors that lack its recycled stretch and Polygiene.
Why this is supported
The I.FIV5 jacket matches the Yarn Yard Windbreaker's
Polygiene technology that eliminates odour and prevents the growth of bacteria
stylight.caand adds
Thick, stretch windproof material made from recycled polyester
stylight.caand
Breathable jersey inserts under the arms
stylight.ca, all at roughly half the sale price. At $39.95 CAD, it undercuts the GapFit Tech and Diadora options while also offering a mock neck that saves the cost of a neck gaiter.
- Shape retention
The stretch knit snaps back without bagging after hundreds of stretches.
Why this is supported
The jacket’s knit construction uses interlocking polyester loops to provide stretch without spandex.
High-quality stretch polyester can elongate 10–20% while maintaining strong rebound after release.
printdoors.comNo spandex means the fabric snaps back without sagging, even after hundreds of stretches.
himfr.com- Fabric durability
The recycled polyester is windproof and as durable as virgin polyester.
Why this is supported
The jacket’s outer fabric is thick and windproof by construction, which also makes it naturally snag- and abrasion-resistant.
Thick, stretch windproof material made from recycled polyester
stylight.caDespite the recycled content, the material’s performance is identical to virgin polyester at the molecular level.
Both recycled and virgin polyester share the same base polymer: polyethylene terephthalate.
natuclothes.com
Image Analysis
3 images- 01
Product
Front view of a fitted black zip-up jacket with a stand collar and long sleeves; zipper is partially open revealing a white polo beneath and sunglasses hooked at the chest.
- SilhouetteFitted, hip-length jacket with a straight hem and narrow shoulders visible from a seated frontal view.
1 region
x 0.06 · y 0.16 · w 0.88 · h 0.68 (high) - Closure and openingCentral front zipper, partially unzipped to mid-chest revealing underlying garment; zipper track visible as a narrow vertical seam.
1 region
x 0.38 · y 0.24 · w 0.22 · h 0.30 (high) - CollarShort stand/up collar that sits close to the neck and remains unfolded when jacket is unzipped.
1 region
x 0.30 · y 0.10 · w 0.40 · h 0.12 (high) - Sleeve cuffsLong sleeves ending in fitted ribbed cuffs that sit snug at the wrists.
2 regions
x 0.10 · y 0.66 · w 0.30 · h 0.22 (high); x 0.60 · y 0.66 · w 0.30 · h 0.22 (high) - Fabric appearanceSmooth, matte knit or woven fabric with no visible texture or pattern in this lighting.
1 region
x 0.12 · y 0.20 · w 0.76 · h 0.60 (high) - Visible accessories on jacketA pair of sunglasses with round amber lenses and dark frames is hooked into the jacket opening at the chest.
1 region
x 0.38 · y 0.36 · w 0.18 · h 0.20 (high)
Other
Lifestyle studio shot showing a seated model wearing the jacket; neutral gradient backdrop, wooden bench with a trophy and golf balls; soft, diffuse lighting.
- Model and poseSeated model leaning slightly forward with hands resting between knees; head facing camera.
1 region
x 0.10 · y 0.02 · w 0.80 · h 0.60 (high) - PropsWooden bench to the right of the model holds a gold trophy on a wooden base and two white golf balls.
1 region
x 0.66 · y 0.52 · w 0.28 · h 0.34 (high) - Background and lightingNeutral warm-gray gradient background with soft, even studio lighting and gentle shadows under the bench.
- Additional garmentsWhite collared polo worn under the jacket and a light-colored baseball cap on the model's head; both partially visible.
1 region
x 0.28 · y 0.08 · w 0.44 · h 0.28 (high) - Image crop and focusTight vertical crop excluding most of the legs below the knees and the top of the cap; subject in sharp focus, shallow depth of field.
Colors
deep black· jacket body and sleeves#0E0E0E- SilhouetteFitted, hip-length jacket with a straight hem and narrow shoulders visible from a seated frontal view.
- 02
Product
Close-up view of the jacket's upper body and right sleeve showing a fitted black stretch fabric, high collar, vertical front zipper, horizontal seam at waist level, and a zippered side pocket with visible metal zipper pull. Model's right hand is inserted into the pocket.
- Overall silhouetteFitted jacket visible from upper torso to hips with a close-fitting high collar and long set-in sleeves; model shown in three-quarter side pose with right arm bent and hand in pocket.
1 region
x 0.06 · y 0.06 · w 0.88 · h 0.88 (medium) - Fabric and finishSmooth, matte black stretch-knit or woven fabric with minimal surface texture visible and slight pulling where seams meet, indicating stretch behavior.
1 region
x 0.12 · y 0.20 · w 0.60 · h 0.62 (high) - High collarClose-fitting tall collar that rises to the model's lower jawline, constructed from same black fabric with a smooth seam at the shoulder.
1 region
x 0.34 · y 0.04 · w 0.30 · h 0.20 (high) - Front zipperVertical central front zipper track visible along the jacket front, matching black tape with stitching visible alongside.
1 region
x 0.06 · y 0.42 · w 0.40 · h 0.44 (medium) - Horizontal waist seamSingle horizontal seam runs across the jacket at upper hip/waist level, creating a panel line.
1 region
x 0.12 · y 0.50 · w 0.68 · h 0.10 (high) - Zippered hand pocketAngled zip pocket on the right side (model left) with visible zipper tape and partially open pocket where model's hand is inserted.
1 region
x 0.12 · y 0.66 · w 0.22 · h 0.22 (high) - Metal zipper pullSmall metallic zipper pull visible at the pocket opening with reflective silver finish.
1 region
x 0.17 · y 0.78 · w 0.05 · h 0.05 (high) - Sleeve cuff detailSleeve ends in a stitched cuff with a subtle seam and slight fabric gather near the wrist.
1 region
x 0.54 · y 0.66 · w 0.38 · h 0.28 (high) - Model hand in pocketModel's right hand and part of forearm visible inserted into the right-side pocket, skin tone visible against black fabric.
1 region
x 0.18 · y 0.72 · w 0.10 · h 0.16 (high)
Other
Studio close-up on a neutral off-white background showing the model from mid-face to hips; soft, even lighting with minimal shadowing and slight highlights on the model's hair. Image cropped at top of head and lower hips.
- Background and lightingUniform off-white background with soft, diffuse lighting that creates gentle shadowing and even illumination across the jacket.
1 region
x 0.00 · y 0.00 · w 1.00 · h 1.00 (high) - Framing and cropImage cropped at top of model's head and lower hips, focusing on upper-body detail and right-side pocket area.
- Model stylingBlonde hair partially covering the collar and chest area; model facing slightly downward and to the left of frame.
1 region
x 0.30 · y 0.00 · w 0.44 · h 0.34 (high)
Colors
deep black· main fabric#0E0D13metallic silver· zipper pull- Overall silhouetteFitted jacket visible from upper torso to hips with a close-fitting high collar and long set-in sleeves; model shown in three-quarter side pose with right arm bent and hand in pocket.
- 03
Product
Rear view of a fitted long-sleeve black jacket on a model showing a raised collar, smooth stretch fabric, subtle side shaping seams, and a small light-colored logo at upper center back.
- Rear silhouetteBack-facing torso of a fitted jacket with a slightly tapered waist and a straight hem that extends to the top of the hips.
1 region
x 0.18 · y 0.26 · w 0.64 · h 0.52 (high) - CollarShort stand-up collar that rises slightly around the neck and lies flat at the back.
1 region
x 0.40 · y 0.12 · w 0.20 · h 0.08 (high) - SleevesLong set-in sleeves with smooth, untextured surface and faint seam lines visible along the shoulder and outer arm.
2 regions
x 0.06 · y 0.32 · w 0.22 · h 0.44 (high); x 0.72 · y 0.32 · w 0.22 · h 0.44 (high) - Material appearanceSmooth, slightly matte stretch fabric with minimal surface texture and small, gentle folds at the lower back.
1 region
x 0.24 · y 0.36 · w 0.52 · h 0.36 (high) - Side shaping seamsVisible vertical seam lines near each side panel suggesting fitted shaping; seams run from underarm toward the hem.
2 regions
x 0.18 · y 0.30 · w 0.12 · h 0.46 (medium); x 0.70 · y 0.30 · w 0.12 · h 0.46 (medium) - Upper back logo tabSmall square light-colored logo or tab centered at the upper back just below the collar.
1 region
x 0.48 · y 0.17 · w 0.03 · h 0.03 (high) - Hem constructionLower edge finished with a narrow folded hem and visible topstitching near the bottom of the jacket.
1 region
x 0.20 · y 0.70 · w 0.60 · h 0.10 (high)
Other
Studio portrait with neutral light background; model shown from the back with head turned to the right, cropped above mid-head; soft, even lighting with subtle shadows.
- Background and stagingUniform light neutral background with no visible props or packaging.
- Model pose and cropModel stands facing away from camera with head turned to the right in three-quarter profile; image cropped slightly above the crown of the head and at the hips.
1 region
x 0.08 · y 0.00 · w 0.84 · h 1.00 (medium) - LightingSoft, diffused studio lighting producing even illumination and gentle shadows along natural contours.
Colors
matte black· main body and sleeves#0E0D13bright white· upper back logo tab- Rear silhouetteBack-facing torso of a fitted jacket with a slightly tapered waist and a straight hem that extends to the top of the hips.