Created by Lemania, the 33.3 caliber chronograph was initially launched in 1933. The early versions were made for the snapback examples (such as this example) and later became anti-choc and anti-magnetic for the waterproof models in 1949.

Cased in a large (37.7 mm) stainless steel case, this example is a rare example of reference 2393 featuring a 4-multi color dial with double tachymeter scale and pulsation scale. For a similar example see Omega, a Journey through Time by Marco Richon, p. 538.