OMEGA Speedmaster Calibre 321

The Omega Speedmaster Calibre 321, reference 311.50.39.30.01.001, is a chronograph with a 38.6 mm white gold case. The case is 13.92 mm thick and measures 48 mm lug to lug. Omega rates the case to 60 metres. Calibre 321 is a manual-winding movement with a 55 hour power reserve. A sapphire crystal with anti-reflective treatment on both sides covers the black dial. The Speedmaster has small seconds and a tachymeter scale, and a display back shows the movement. A white gold bracelet is fitted to the watch, with a foldover clasp that has a comfort setting.