Sinn watch 757 diapal leather sinns watches diapal technology is an amazing breakthrough since it has allowed for the utilization of a lubrication free escapement mechanism this innovation increases the accuracy of the watch in the long run the 757 diapal timepiece comes with valjoux 7750 automatic calibre that performs 28 800 vibrations per hour and has 25 bearing jewels the case is hardened through the use of tegiment technology a dehumidifying capsule protects the mechanism from fogging