Heuer Carrera Ref 3647d Blue Decima ScaleTHE HEUER DECIMA SCALE CARRERA This cool Heuer chrono is a rare iteration of the legendary Carrera, one of Jack Heuers most important creations. Measuring 36mm across, this is a good sized chrono with two register layout and unusual blue decima scale, which is referenced by the d in the reference number(used for counting production numbers!). The cream dial has a raised outer seconds track and in from that is the unusual decimal scale in blue. The