A Rolex Sea-Dweller 'Great White' Wristwatch. Ref 1665/0. Circa 1977. 40 mm stainless steel case, bi-directional bezel, aluminium graduated insert. Automatic mechanical movement Rolex Calibre 1575, Black MK1 dial, with tritium luminous markings, domed mineral crystal glass, oyster bracelet ref 93150. Swiss made.