The dial has to be studied closely here. It is one of the finest black, textured dials we have seen. Only a slight lume dropout from the minute hand makes it not completely perfect. The hour markers are great too. This marvelous Certina has model number 5101 011, serial 4522053. It has the 17 jewel caliber 25-36 manual movement beating at 19800/hour. Case diameter 34,3mm, year of production 1963.