Sinn watch u2 ezm 5 leather u2 is a professional diving mission timer what makes it particularly unique is the usage of submarine steel in the production process this material has magnetic resistance properties that make it very suitable for divers it performs 28 800 vibrations per hour and has 21 bearing jewels additional features include a dehumidifying technology captive divers bezel with minute ratcheting crown at 4 o clock mission timer design second time zone and scratch resist