The Omega Constellation 551 Certified Chronometer was one of the finest Omega watches of the 1960s. Fine timekeeping is achievable with the micro-regulator. The main differences between this Omega and the Rolex 1030 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 hairspring 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.