Omega Style No: 332.12.41.51.01.001 Omega Speedmaster '57 Co-Axial Master Chronometer Chronograph - 40.5 mm Steel Case - Black Dial

40.5 mm steel case, transparent back, brushed bezel with blackened tachymeter scale, scratch-resistant sapphire crystal with anti-reflective treatment on both sides, black dial with recessed hour markers showing vintage Super-LumiNova from beneath, Calibre 9906 manual-winding chronometer movement with chronograph, small seconds, and date. Water resistant to 50 metres (167 feet).