Sinn watch flieger chronograph 103 st sa vintageleather sinn 103 is a largely functional watch designed to resemble the cockpit instruments that pilots rely on this watch comes with valjoux 7750 automatic calibre it performs 28 800 vibrations per hour and has 25 bearing jewels the movement features protection against magnetic influences and shock resistance a 42 hour power reserve is available additional functionalities include a captive pilots bezel with minute ratcheting chronograph