Tauchmeister T0249 GMT XL 1000m Dive Watch with Helium Release ValveThis is a serious dive watch. It features a helium release valve at the ten o'clock position (allows gas build-up to escape to prevent damage to the watch), a screw-in crown, special coated luminous hands and markers for great visibility in the dark, a scratch resistant sapphire crystal, uni-directional rotating bezel, a retrograde style 2nd time zone (GMT indicator) at 12:00, a high quality Cal.GP01 quartz movement, a screwed-in (moderate temperature assembled) case back, 1000 meter water resistancy, orange hands and markers, and a high quality dive strap.