Sinn watch 757 s utc leather sinns 757 instrument chronograph watches were designed to be very resilient and protected from external influences this timepiece is equipped with valjoux 7750 automatic calibre that performs 28 800 vibrations per hour and has 25 bearing jewels the case is hardened using sinns tegiment technology a dehumidifying capsule increases readability and protects the mechanism additional functionalities include a second time zone a date window is positioned at 4 o clock