Rolex Explorer Ref. 6350 was produced in 1953 for only about one year or so, then it was replaced by Ref. 6150 in the same year. The black dial of most Explorer Ref. 6350 was printed “Officially Certified Chronometer” words, the dial even had unique Honeycomb decoration. Ref. 6150 and Ref. 6350 all adopted A296 movement, but the case diameter of the latter was 2mm larger than the former, Ref. 6350 were all Precision models.