Rolex Oyster Perpetual Datejust of four
 

Oyster highly accurate self-winding movement entirely designed and manufactured by Rolex. Rugged, reliable, every movement can guarantee long-term high-performance operation, and received an official identification of the Swiss certificate of approval-hours. Swiss Precision Clock Test Center (cosc), each only go through the Swiss precision movement Rolex Clock Test Center (cosc) of the rigorous testing. Stringent tests required movements in five different locations and three different temperatures for 15 consecutive days and nights after the test. To obtain an official identification of the Swiss certificate of approval-hours,cheap watches, every movement must have successfully passed the cosc testing.