Oyster Perpetual 6564

34 mm, 12 mm-thick Oyster Perpetual chronometerChronometerA watch or movement certified for timekeeping precision under a defined testing standard. The applicable certification depends on its maker and period; it is not the same as a chronograph. with a plain polished bezelBezelThe frame surrounding the crystal at the front of a watch. and cal. 1030. Identical to the 6565 (engine-turnedGuillochéDecorative patterns engraved into a surface with an engine-turning machine. Similar-looking patterns do not by themselves establish how a dial was made. ) and 6567 (reeded ) apart from the ; cases and backs were interchangeable. Dr. Crott says it began as an Explorer-inspired model and ran for about 30 years.