This is the transitional Omega Constellation watch when Omega ended the 500 series calibers and introduced the 550 series calibers to the market. The case design is quite similar to the 50's Constellation model. This model was introduced in 1959 and lasted to early 1961. Very rare black factory original finish dial is nicely aged. Enlarge photos to view imperfection on the aged dial. It is also the only case model that never used the words "officially certified" on the dial even though the watch is officially certified. Omega wanted to provide a less cluttered Constellation dial at the time. The original case is made of solid stainless steel with a solid gold case back medallion and in very good unpolished condition. Case model is 14393-3 SC and measures 34.7mm across excluding the crown by 43.6mm lug tip to lug tip. Original signed crown. Brand new crystal and new case back gasket. The automatic movement is an Omega caliber 561 with 24 jewels. Movement serial is 17554411 dating this watch to 1960. It has been professionally serviced and ready for everyday wearing. Comes complete with a matching 18mm high quality genuine leather strap. Wrist size in photo is 6 inches.