Omega Seamaster Diver 300M Co-Axial Master Chronometer Watch - 43.5 mm Black Ceramic Case - Brushed Black Ceramic [Zro2] Dial - 5-Stripe Black And Grey Nato Strap - 210.92.44.20.01.00243. 5 mm black ceramic case with helium escape valve, transparent back, bezel with a white enamel diving scale, domed scratch resistant sapphire crystal anti reflective treatment on both sides, brushed black ceramic [ZrO2] dial with laser engraving to create raised waves, Caliber Omega 8806 self winding movement with a co axial escapement, chronometer, approximately 55 hours of power reserve, 5 stripe black and grey NATO strap. Water resistant to 30