Omega Speedmaster '57 Co-Axial Chronograph Watch - 41.5 mm Steel And Red Gold Case - Black Dial - Steel Bracelet - 331.20.42.51.01.002 Quilted transparent back set with a

transparent back set with a yellow gold central Observatory medallion

circular-grained external zone

44 mm steel and yellow gold case with anti-magnetic protection and helium escape valve

black counters

24 mm stainless steel and 18K yellow gold case

Omega Speedmaster '57 Co-Axial Chronograph Watch - 41.5 mm Steel And Red Gold Case - Black Dial - Steel Bracelet - 331.20.42.51.01.002 Quilted transparent back set with a41. 5 mm stainless steel and red gold case, transparent back, 18K red gold bezel with tachymeter scale, scratch resistant sapphire crystal with anti reflective treatment on both sides, black dial with a seconds sub dial at 9 oclock and a 12 hour and 60 minute chronograph recorder on the sub dial at 3 oclock, calibre 9300 self winding movement with a central chronograph seconds hand and a date window at 6 oclock, approximately 60 hours of power