Calibre 3600 is an automatic rattrapante chronograph movement from Omega based on the ETA 7750.
Cal. 3600 first appeared in 1999 in the Omega Speedmaster Rattrapante, Ref. 3540. It used an ETA 7750 ebauche but included a rattrapante mechanism with an extra pusher at 10 00. Production lasted only to 2001 or 2002.