A 1965 Omega Seamaster 120 Divers watch with faded to grey rotational bezel, and black matte dial with tritium indexes. The watch is in original condition and has a lovely original patina developing on the hands and hour markers. 
 
The manua wind versions of this model seem harder to find in good, original condition, like this one.
 
This fills a gap in your Omega collection, and makes a nice change of proportion from the larger Omega Divers like the 300's.
 
The watch is reference 135.027 and has the manual caliber 601 with 17 jewels.