The 900 pilot watch is the largest instrument chronograph designed by sinn its case diameter is 44 millimetres its movement is valjoux 7750 automatic that performs 28 800 vibrations per hour and has 26 bearing jewels extreme protection from magnetic influences is one of the watchs most special characteristics the case is hardened through the use of sinns tegiment technology a dehumidifying capsule protects the dial from fogging additional functionalities include a rotating elapsed time