Rolex Oyster Perpetual
Rolex's first self-winding wristwatch, wound by a freely swinging rotor.
In 1931 Rolex patented a semicircular rotor that swung freely in both directions and wound the spring as the arm moved. Together with the waterproof Oyster case of 1926 it became the basis of almost all Rolex's later models.
Materials: Steel or gold, glass; self-winding movement with rotor
Manufacture: Made in Geneva and Biel; the waterproof Oyster case is screwed together.
The fluted or smooth case with a screw-down crown.
The word Perpetual on the dial under the Rolex crown.