Omega, "Speed-master". Produced in the 1970's.Fine, water-resistant, stainless steel gentleman's wristwatch with blue bezel, round button chronograph, register and tachometer. Accompanied by a box. three-body, polished and brushed, screwed-down case back engraved with the Speedmaster logo, antimagnetic protecting shield, tachometer graduation on the bezel. black with tritium-coated indexes, auxiliary dials for the seconds, the 12 hour and 30 minute regis-ters. "Skeleton" tritium-coated hands. Cal. 321, copper-colored, 17 jewels, straight line lever escapement, mono-metallic balance, shock-absorber, self-compen-sating Breguet balance-spring.Dial, case and movement signed.Diam. 40 mm.