Omega

         The Omega Constellation 551 Certified Chronometer was one of the finest Omega watches of the 1960's. Fine timekeeping is achievable with the micro-regulator. The main differences between this Omega and the Rolex in this website are in the balance wheel and hairspring. The greatest difference between superior timekeepers and other watches is found in the formation of the hairspring. The Rolex has a white alloy hairspring (probably Invar) with a Breguet overcoil, whereas the Omega hairspring is flat. Collectors should not overlook this watch, especially since it can be bought for a small fraction of the price of a comparable Rolex.