The Soviets introduced a new chronograph caliber in 1976 which was designated the 3133. It was based on the Valjoux 7734 for which the Soviets had purchased the machinery from the Swiss in 1974. The Soviets made a number of modifications to the 7734, but many of the parts remain interchangeable. The new chronograph calibre entered service in 1976 in the OCEAN, and was initially exclusively used by the Soviet Navy. USSR mechanical Poljot /caliber 3133, hand-winding, shock protection, 23 stones, day power reserve with Chrono activated: deactivate 37 hours / Chrono: 42 hours Diameter: 3,8 mm, height: 14 mm. For straps with 18 mm width. Worn but very good condition. The case has some superficial signs of wear in accordance with its age. Please assess the photos with care. Watch, chronograph and date works great. Total watch weight: 74,5 g. Leather strap, 18 cm long, with slight wear marks Beautiful for a collector or for daily use. Will be carefully packaged and shipped insured with Track & Trace code.