Omega Planet Ocean 600M Co-Axial Master Chronometer Watch - 39.5 mm Sedna Gold Case - Unidirectional Brown Cermaic Bezel - Chocolate Brown Dial - Brown Leather Strap - 215.63.40.20.13.00139. 5 mm 18K Sedna gold case with helium escape valve, transparent screw in back, screw in crown, unidirectional rotating brown cermaic bezel with Ceragold diving scale, domed scratch resistant sapphire crystal with anti reflective treatment on both sides, chocolate brown dial with Arabic numerals and a date window at the 3 oclock, caliber 8801 self winding Co Axial chronometer movement with date function, approximately 55 hours of power reserve,