Ebauches SA prototype, Certina Chronolympic, valjoux 728

Extremely rare Ebauches SA (ESA/ETA) prototype for Certina, first Certina Chronolympic Regatta ever produced, powered by one of the rarest valjoux movement.

Column wheel movement ESA Valjoux 728, the first regatta movement with the minute chronograph counter placed in the center.

Manual winding. No date
Center Chronominute and seconds
Hour counter at 6
Production date estimation  1971

Case size without crown W40xH44mm