1950s: A Technical Breakthrough
The 1950s marked a turning point in watchmaking, as waterproof technology expanded the utility of watches to aquatic environments. Leather remained the strap material of choice, prompting the development of water-resistant treatments. Interestingly, stainless-steel bracelets—despite their durability—never claimed top popularity during this period.
1960s: Enter the TROPIC Strap
Rubber strap innovation began in the 1960s with the emergence of the TROPIC strap. While revolutionary, early versions were stiff, brittle, and uncomfortable against the skin. That’s when ISOfrane® challenged the status quo.
Inspired by Automotive Engineering
ISOfrane® introduced a breakthrough approach: leveraging the same rubber compound used in automotive tires—engineered to withstand heat, rain, ice, and chemical exposure without degrading. This durable material became the foundation for what would become the most resilient waterproof watch strap ever made.
Design Meets Functionality
ISOfrane® didn’t stop at durability. The brand pioneered comfort-driven design with wide ventilation slots for breathability and a textured underside that prevented sticking to skin. This combination of toughness and comfort redefined dive watch wearability.
ISOwhat?
Our original ISOfrane® watch bands were manufactured using a compound called isoprene. And just what is isoprene? Isoprene is a, liquid hydrocarbon that is obtained in the processing of petroleum and is used as a raw, chemical material. Isoprene was far more durable, and maintained its looks.
ISOfrane® today..
We used the best recipe, made it non-allergic, non-toxic and added even more durability and softness to rubber WITHOUT using silicon (the dust magnet) to bring back the legendary ISOfrane® dive watch band, which is possibly the best watch strap you’ll ever buy.
After production ceased in the 1980s, original ISOfrane straps became collector's relics — auctioned at prices far beyond reach. In 2010, SYNCHRON the Austrian watchmaking house behind Synchron, Aquadive, and Aquastar — acquired the brand and revived it. Led by dive watch enthusiast Rick Marei (who also famously revived Doxa), Synchron reintroduced ISOfrane with the same obsessive attention to detail as the originals, while perfecting the rubber formula for even greater longevity.
After production ceased in the 1980s, original ISOfrane straps became collector's relics — auctioned at prices far beyond reach. In 2010, SYNCHRON the Austrian watchmaking house behind Synchron, Aquadive, and Aquastar — acquired the brand and revived it. Led by dive watch enthusiast Rick Marei (who also famously revived Doxa), Synchron reintroduced ISOfrane with the same obsessive attention to detail as the originals, while perfecting the rubber formula for even greater longevity.
Modern ISOfrane straps are crafted in Italy, where the proprietary natural rubber compound is formulated and finished to exacting standards. Italy's heritage in precision manufacturing ensures every strap upholds the quality the brand has stood for since the 1960s.
Today's ISOfrane straps are made from natural rubber — not silicone, not synthetic alternatives. Natural rubber offers an exceptional combination of suppleness, grip, and tactile warmth that synthetic materials simply cannot replicate. It moulds gently to the wrist over time, becoming more comfortable with every wear. The compound is PFAS-free and non-toxic, making it as responsible a choice as it is a pleasurable one.
Natural rubber on its own will crack, harden, and perish over time when exposed to UV light, ozone, heat, and oils. ISOfrane addresses this with a proprietary blend of formula additives developed specifically to counteract these vulnerabilities — stabilising the compound against oxidation, UV degradation, and environmental stress. Crucially, these additives are PFAS-free and entirely non-toxic, so there is no trade-off between performance and safety. The result is a strap that retains the luxurious feel of natural rubber while offering a lifespan that far exceeds untreated rubber or common silicone alternatives.
PFAS (per- and polyfluoroalkyl substances) are a class of synthetic chemicals widely used in manufacturing for their water and heat resistance. They are persistent in the environment and in the human body, earning them the nickname 'forever chemicals', and are increasingly linked to health concerns with long-term exposure. Many rubber and coating products still rely on them. ISOfrane's natural rubber compound contains no PFAS whatsoever — a deliberate formulation choice that means the strap is safe against your skin day after day, dive after dive, without compromise.
Silicone is inexpensive and technically waterproof, but it attracts dust and lint, feels plasticky against the skin, and lacks structural integrity under tension. Natural rubber has a living quality to it — it flexes without resistance, grips the wrist without sticking, and develops a subtle patina with age. Combined with ISOfrane's PFAS-free, non-toxic anti-perishing additives, it delivers a wearing experience no silicone strap can match.
Yes, completely. ISOfrane straps are 100% silicone-free, PFAS-free, and non-toxic. The proprietary formula has been developed with skin safety as a priority, making it suitable for everyday wear even for those with sensitivities. The strap does not attract dust or lint, and the textured underside prevents it from adhering uncomfortably to skin.
The iconic ladder-style ventilation slots are functional engineering at its finest. The slots allow airflow across the wrist, prevent moisture buildup, and ensure water drains instantly when diving. The ribbed textured underside stops the strap adhering to skin, while the natural rubber compound flexes with the wrist rather than against it — a combination that has never needed improving since its introduction.
ISOfrane straps are available in standard dive watch lug widths, most commonly 20mm, 22mm, and 24mm. The 24mm 'ladder' strap is the most iconic format, synonymous with the original Omega PloProf. Check the product pages for current availability in each width.
ISOfrane straps are designed with micro-adjustability in mind. The tang hole spacing is closer than standard straps, allowing a more precise fit. Crucially, the natural rubber compound has an inherent 'give' — it expands and contracts with temperature changes and wrist swelling, which is especially useful when transitioning between cold water and warm air while diving. Choose the hole that feels comfortably snug, not tight.
Yes. ISOfrane straps are available worldwide through isofrane.com and authorised retailers. Shipping times and costs vary by destination. For the most current shipping options and rates, please refer to the checkout page or contact the ISOfrane team directly.
ISOfrane stands behind the quality of every strap. If you receive a defective item or are unsatisfied with your order, please contact the ISOfrane team within 14 days of receipt to discuss a return or exchange. Items must be unworn and in original packaging. For the most up-to-date return policy, visit the Returns page on the website.
ISOfrane straps are remarkably low-maintenance. After diving or heavy use, rinse with fresh water and allow to air dry away from direct sunlight. For a deeper clean, mild soap and warm water is all that is needed. Avoid harsh solvents, bleach, or petroleum-based cleaners, which can strip the protective additives from the natural rubber compound.
Thanks to the proprietary anti-perishing additives, a well-maintained ISOfrane strap will outlast the vast majority of rubber and silicone straps on the market. The natural rubber resists cracking, hardening, and UV degradation far beyond what untreated rubber could achieve. Store in a cool, dry place away from prolonged sunlight when not in use, and the strap will reward you with years — potentially decades — of wear.
Absolutely — it was made for exactly this. The natural rubber compound, fortified with ISOfrane's protective additives, is resistant to salt water and chlorine. Simply rinse with fresh water afterward to remove any residue and preserve the rubber. The strap will not stiffen, discolour, or degrade from regular aquatic use.
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