Omega Seamaster Planet Ocean 600M Co-Axial Master Chronometer Watch - 39.5 mm Black Ceramic Case - Unidirectional Bezel - Black Ceramic Dial - Quilted Black Rubber Strap - 215.92.40.20.01.00139. 5 mm black ceramic case with helium escape valve, transparent back, unidirectional rotating bezel with a white enamel diving scale, domed scratch resistant sapphire crystal anti reflective treatment on both sides, black ceramic dial with 18K white gold numerals, indexes and hands, as well as a date window at 3 oclock, Caliber Omega 8800 self winding movement with co axial escapement, chronometer, date, approximately 55 hours of power reserve,