The 1965 diver’s watch incorporated an automatic mechanical caliber and delivered 150m water resistance. The watch was designed for maximum reliability and legibility in the harshest conditions and proved its reliability when used in the Antarctic during the 60s and laid the path to the development of future landmark watches. Stainless steel Screw case back Screw down crown Sapphire crystal Color Black Lumibrite Dial Markers , Indexes Lumibrite Japan mechanical caliber 6R35 Water resistance : 200 M Comes with Polyester straps : 2 Pin buckle