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Sinn Releases The DuoFlex Diving Watch Strap System

Sinn Releases The DuoFlex Diving Watch Strap System News Today, German brand Sinn, best known for its rugged tool and dive watches, announced a new strap system specially designed for active divers. The Sinn Duoflex Diving System aims to tackle a situation well-known to recreational and professional divers — the need for a diving watch that can quickly and easily be adjusted to fit over a wetsuit. And while you might assume (as I did) that most extension clasps are designed to address this exact problem, many of them are, apparently, inadequate and unable to extend enough to accommodate the increased wrist diameter when suited-up.

Sinn Releases The DuoFlex Diving Watch Strap System News

While this new expansion pack (which can be retrofitted to your existing 44mm U-series model or purchased as an upgrade should you be about to buy a Sinn U-series watch) comes with its own extension clasp, which will enable wearers to quickly adjust the length of their strap by 5mm in either direction, the real novelty of this release can be found in the special lug extensions included in the kit.

Sinn Releases The DuoFlex Diving Watch Strap System News

Sinn’s solution requires your dive watch to be fitted with special proprietary end lugs. These lugs come in either uncoated or black PVD so they can be selected to match/contrast with your case metal as you see fit. This system will work with any U-series model with a 44mm diameter, and you can choose whichever color silicon strap you want out of a generous range of five colors. You can have either red, green, blue, black, or white.

Sinn Releases The DuoFlex Diving Watch Strap System News

The system is very simple. The silicon strap (which is cut to the correct length by the wearer) can be hooked onto a spring bar that sits within the specially-formed lug extension (which is necessary as the strap requires the top-down friction of a “hooded” lug to remain in place). Sinn claims that when the watch is on the wrist it can withstand the same force as a traditionally affixed timepiece without becoming dislodged.

Sinn Releases The DuoFlex Diving Watch Strap System News

It seems to me that the best way to use this system as it was intended is to have two of these straps (one cut to the length you would want on a daily basis and one cut to the length appropriate to your wetsuit) as otherwise it seems likely that this strap system’s extension clasp would run into the same problem it is trying to solve. For pricing information, Sinn advises that customers contact their nearest authorized dealer. As an existing owner of a Sinn Hydro UX, I would be interested to see how useful, easy-to-use, and reliable this new system is and will endeavor to put it through its paces in due course. For more information, please visit

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  • RJ

    using two straps seems a bit more or a hassle than just the diver extension

  • iotion

    I feel like this would look a LOT better if they blacked out those strap bars. Wouldn’t look as obvious on a black rubber strap.

  • SuperStrapper



    Awesome the answer to a question no one asked ….

  • spice

    Interesting but confusing – greater clarity required, I think, Mr Nudds?

  • Zed

    I admit I don’t understand how it works.
    But a simple solution like the rolex extensible clasp?

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