23 jewel automatic, self-winding mechanical movement winds from the motion of your wrist - no batteries to change. 40 hour power reserve Overwind prevention function Convenient day and date display can be set to display day in English or Spanish 100 meters water resistant (suitable for swimming or snorkeling, but not diving. LumiBrite hands, markers and bezel for night-time visibility. Solid stainless steel case and bracelet in brushed finish with polished accents Case has screw-down see through caseback that allows you to see the workings of the automatic movement Stainless steel bracelet with triple fold safety clasp Hardlex crystal is scratch resistant Approximate case dimensions, 38mm wide and 12 mm thick