Oyster Perpetual Bubbleback 2940

Bubbleback in a tonneau-shaped case, signed “Oyster Perpetual” and often “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.”. Patrizzi’s Rolex book lists it as the “Rigid Hooded” model; examples date from about 1940 to 1946.