OMEGA 27-CHRO-C12

The Movement cal 27-CHRO-12 changed name to 321 in 1949. This famous small 27mm caliber was designed by the famous Technician at Lemania Albert Piquet and released in 1942.

under the balance you can see some of the caliber nr 27CHRO-C12. 27 is equal to the diameter of the movement.