This is a solid 18k white gold variant that is not as common as the yellow gold version as indicatec by the final digit "9" in Rolex reference codina svstem The model was produced between approximately 1977 and 1988 and was a transitional model that evolved to a more practical offering with sapphire crystal and single quickset date complication for those whom seek a vintage watch that can be thrown in a reqular rotation. Movement: Caliber 3055, a high-beat movement 28,800 automatic and single quickset.