Sinn has long used the Valjoux 7750 movement for their chronograph watches, but began reworking the movement in 2003 as the SZ01. This was followed in 2006 with this Cal. SZ02. The main difference being a 60 minute (rather than 30 minute) chronograph counter.
Once again, for the SZ02, Sinn reworked the chronograph counters. This movement was designed to be rotated 180 degrees, with the crown and pushers on the left. In this orientation, chronograph minutes are displayed in a subdial at 6:00 with chronograph hours at 12:00. The minutes counter is a full 60, however, unlike the Valjoux. Small seconds are displayed at 3:00.