Sinn Spezialuhren SZ02

SZ02 is an automatic chronograph caliber manufactured by Sinn Spezialuhren. Based on the Valjoux 7750, it modifies the 12 o'clock counter to display 60 minutes rather than the standard 30, and is designated as a 60-minute totalizer. The movement features Sinn's DIAPAL low-friction escapement, Ar-dehumidifying technology, and Tegiment hardening treatment. It remains in production and powers the 103 and 203 watch variants.