Sinn watch 757 s leather the 757 s model is part of sinns instrumen chronographs line the watch comes equipped with valjoux 7750 automatic calibre that performs 28 800 vibrations per hour and has 25 bearing jewels the case is extra strong because of sinns tegiment technology the brands special dehumidifying technology is used as well another intriguing characteristic is the extreme protection from magnetic influences the timepiece is equipped with various functionalities including captiv