The Rolex chronograph ref. 6238 was produced from the early 1960’s to 1967. It has a more modern look than the previous chronographs issued by the brand, but still carries the inner tachymetric scale and outside smooth bezel that are typical of the 1950’s. It is often referred to as “pre Daytona”, as it somewhat a transition from the classical chronographs to the Daytona that was issued in 1963.