This watch was made in 1973 to commemorate the 125th anniversary of Omega. It is also the first automatic chronograph, that also carries the certificate of the Swiss Institutes for Official Chronometer Tests. (COSC) The Speedmaster125 was produced as a limited run of 2,000 pieces. Unlike other Speedmaster commemorative or limited editions, no engraving was done on the case or the case back of the watch.