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March 2023 Notice: It's here. The next iteration of the Spiralwinder Watch Parts exhibition caseback has arrived!


The Next Generation:

Our new caseback is thinner than any caseback made for the Speedmaster, ever. Redesigned from the ground up, we've developed a brand new ultra-thin profile that reduces height by over a millimeter. This novel slimness will emphasize the elegant contours of your Speedmaster's case and simultaneously improve the overall ergonomics of your watch.


How it's Made:

Our caseback consists of an outer ring, which we precision machine from 316L stainless steel. Then, we sandblast the slots for the opener tool, eliminating machining marks. This also provides contrast to the polished double-bevel, a feature of pre-moon references which we recreate on each caseback to stay true to the Speedmaster's roots. 


After polishing the double-bevel to a mirror finish, the steel ring is carefully fitted with a scratch-resistant sapphire crystal. We apply a colorless, multi-layer AR coating to it, ensuring clear viewing and photos of your movement.


The result is a finished piece fit for the venerable calibre 321, or it's 861 and 1861 descendants. 


If you have any questions, send us a message!

Sapphire Exhibition Caseback for the Omega Speedmaster

SKU: A1-CB3-2021
  • This caseback fits the following references:

    CK2915 / CK2998

    105.002 / 105.003

    105.012 / 145.012 / 145.0012

    145.022 / 145.0022

    3750.50 / 3570.50.00 / 3594.50

    311. / 311.

    311. / 311.

    It will also fit a plethora of modern models, such as the 1861 Professional (3570.50, 3594.50, etc), and FOIS versions. It is not designed for the 1957 Trilogy Speedmaster, the new 3861 Speedmaster, or any 3861-equipped watch. 

    Dec 2022 - We have been informed that the ck2998 models (Blue Panda, Hodinkee H10, Black Pulsometre) utilize different threading compared to the mainline pre-3861 Speedmasters, as do the Tokyo 2020 Speedmasters. These watches will not be compatible with this caseback. 

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