The Sinn 657 S is available on both strap and bracelet and is housed in a 40mm case that is 12mm thick. The 657 S was revealed by Sinn at Basel 2008 and has been very well-received by Sinn collectors.
Based on the Sinn 656 series, the 657 features a larger 40mm case size and a rotating bezel. Also, water resistance has been doubled to 200 meters.
The Sinn 657 S features a black chrome finish with a black anodized aluminum ring bezel. The bezel is screwed to the 657′s case and the automatic movement is well-protected against becoming magnetized due to a special iron core.
A sapphire glass crystal covers the dial of the watch and is treated on both sides with an anti-reflective coating.