Sinns watches for divers brag extreme accuracy and resilience under even the harshest of conditions this watch is equipped with valjoux 7750 automatic calibre that performs 28 800 vibrations per hour and has 25 bearing jewels additional functionalities include divers bezel with minute ratcheting pressure resistance solid case back complete chronograph functions a day and date window located at the 3 oclock mark and scratch resistant sapphire crystal glass with anti reflective coating