Omega Seamaster Diver 300 M Co-Axial GMT Chronograph Watch - 44 mm Steel Case - Matt Blue Ceramic Bezel - Matt Blue Dial - 212.30.44.52.03.00144 mm stainless steel case, sapphire back, screw in crown, matt blue ceramic bezel with unidirectional rotating, domed scratch resistant sapphire crystal with anti reflective treatment on both sides, matt blue dial with yellow GMT hand that matches the yellow 24 hour scale on the dial which makes it possible to keep track of time in a second time zone, caliber 3603 self winding movement with chronograph features with a small seconds sub dial,