Rolex Chronograph 3997

The Reference 3997 is an early and uncommon non-Oyster chronograph from the 1940s. Its technical specification is a two-register chronograph layout, typically powered by the Valjoux 23 manual-wind movement. It is characterized by its smaller case size, measuring approximately 33mm in diameter, which was a standard men’s size for the era. The case, often found in stainless steel or gold, features a snap-on case back and simple pump pushers. Its significance lies in its representation of the classic, smaller European dress chronograph style.