Omega Seamaster Planet Ocean 600M Co-Axial Master Chronometer Watch - 39.5 mm Brown Ceramic Case - Unidirectional Bezel - Brown Ceramic Dial - Quilted Brown Rubber Strap - 215.62.40.20.13.00139. 5 mm brown ceramic case with helium escape valve, transparent back, unidirectional rotating bezel with OMEGA Ceragold technology used to create the diving scale, domed scratch resistant sapphire crystal anti reflective treatment on both sides, brown ceramic dial with 18K Sedna 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