OMEGA Seamaster Aqua Terra 150m Co-Axial Day-Date 41.5mm Watch

Label given to a watch which has undergone precision tests and received a certificate from an official body (COSC).

Day-Date

Apertures which display both the day of the month (numerical) and the day of the week.

Screw-in crown

Self-locking crown, screwed into the tube of the case, used for highly water resistant divers’ watches.

Transparent case back

A transparent case back – frequently made of sapphire – makes it possible to see the movement inside the watch.