ROLEX REF. 1665 DOUBLE RED SEA DWELLER MARK IV STEEL Rolex, Oyster Perpetual Date, Sea-Dweller, Submariner 2000, 2000 ft./610 m., Superlative Chronometer, Officially Certified, Ref. 1665. Made in 1975. Fine and rare, center seconds, self-winding, water resistant, stainless steel diver's Chronometer wristwatch with double red Sea-Dweller logo, helium escape valve, date and a stainless steel Fliplock Oyster bracelet. Three-body, polished and brushed, screw-down case back and crown, helium escape valve at 9, graduated bidirectional revolving black bezel for the decompression times, Triplock winding crown protected by the crown guard. Black with luminous round, triangular and baton indexes, outer minute/ seconds track, aperture for the date, Sea-Dweller Submariner 2000 in red letters. Luminous steel skeleton hands. Cal. 1570, rhodium-plated, oeil-de-perdrix decoration, 26 jewels, straight-line lever escapement, monometallic balance adjusted to temperatures and 5 positions, shock absorber, self-compensating freesprung Breguet balance spring, Microstella regulating screws, hack mechanism.