Omega Speedmaster
Professional
Case Diameter: 42 mm
Case Height: 13.5 mm
Case length: 48.5 mm
Lug Width: 20 mm
Movement: Omega cal. 861
manual wind chronograph, 17
jewel, 21,600 bph, 50  hour
power reserve
Case material: Stainless steel
w/ screw down display back
Crown: Non screw down
Bezel: Non rotating tachymeter
type
Water resistance: 30 meters
Vintage: 1990

This was the "issue" watch for
all NASA Apollo Mission
Astronauts.