Sinn watch 757 utc leather sinns 757 timepieces are built upon the successful 756 range of instrument chronographs this watch is equipped with valjoux 7750 automatic calibre that performs 28 800 vibrations per hour and has 25 bearing jewels one of the timepieces most prominent features is the extreme protection from magnetic influences sinns tegiment technology is used to make the case extra hard a dehumidifying capsule protects the dial from fogging additional features include a date win