Omega. A stainless steel manual wind chronograph wristwatch Speedmaster Professional, Ref 105.012-66, Circa 1966Omega. A stainless steel manual wind chronograph wristwatchModel: Speedmaster ProfessionalReference: 105.012-66Date: Circa 1966Movement: 17-jewel Cal.321 manual wind, No.24539675Dial: Black, luminous baton hour markers, white outer 1/5th second divisions, subsidiary dials at 3, 6 and 9 for seconds, 30 minute and 12 hour recording, white pointed baton hands with luminous inserts, centre chronograph handCase: Brushed and polished tonneau form, screw down back stamped CB for La Centrale Boites, twisted lugs, shouldered crown flanked by twin chronograph pushers, black tachymetre insert to bezelStrap/Bracelet: Black Omega alligatorBuckle/Clasp: Signed steel buckleSigned: Case, dial & movementSize: 40mmThe Omega Speedmaster has enjoyed great popularity among watch collectors throughout the years and is seen as a true design classic today. The current example carries the reference number 105.012, which appeared in the first quarter of 1964. The 105.012 was the first of the 'Speedies' to have Professional on the dial, commonly believed to be a result of NASA certifying the Speedmaster as suitable for their astronauts to use in Outer Space in 1965. Research undertaken between Omega and Anthony Marquie and Gregoire Rossier, authors of Moonwatch Only, have since highlighted that there is evidence of Professional appearing on 105.012s right from the beginning of 1964 thus dispelling this once popular myth.