ROLEX, REF. 4500, A STEEL CHRONOGRAPH WRISTWATCH WITH GOLD HOUR MARKERS CIRCA: 1959CASE MATERIAL: SteelCASE DIAMETER: 36mmSERIAL NO’: 497475DIAL: White     MOVEMENT: Manual FUNCTIONS: Chronograph BOX: NoPAPERS: NoReference 4500 is one of the very few Oyster chronograph models produced by Rolex featuring only a 30 minutes register but leaving out the 12 hours counter. This renders the watch a smoother, more subtle and less sporty design.