The Constellation range appeared at Omega in 1952. The movements are chronometer certified and the case backs are engraved with the image of the Geneva observatory as well as eight stars.
You can follow the review of an Omega Constellation with the same caliber in this blog article:
Bracelet: 19 mm Omega steel for a wrist with a maximum circumference of 18 cm
Condition: Superb condition, this watch has never been polished. The acrylic glass is original Omega. I can't find any traces of this Omega steel bracelet, perhaps it must find its place on another reference but it suits our Constellation perfectly. Very good condition for its age.The movement has been completely overhauled, this Omega works perfectly.
