Sinn watch 900 pilot s sinns 900 range of instrument chronographs is the largest that the company has designed the case diameter is 44 millimetres the 900 pilot s watch is an all black instrument it is equipped with valjoux 7750 automatic calibre that performs 28 800 vibrations per hour and has 26 bearing jewels both the case and bracelet are hardened through the use of sinns tegiment technology a dehumidifying capsule keeps the dial from fogging the watch is also protected from magnet