OMEGA Seamaster Diver 300M

Omega Seamaster Diver 300M 210.30.44.51.01.001 is a chronograph in a 44 mm steel case. Thickness runs to 17.2 mm with a lug-to-lug of 52.8 mm, and a unidirectional rotating bezel surrounds the black dial. A domed, scratch-resistant sapphire crystal with antireflective treatment on both sides covers the dial. Inside is the self-winding calibre 9900, a column-wheel chronograph with Co-Axial escapement and silicon balance spring, certified as a Master Chronometer and resistant to magnetic fields up to 15,000 gauss. The date and small seconds appear alongside the chronograph, and the caseback is transparent. A steel bracelet with a foldover clasp and diver extension completes the piece. The screw-down crown and helium valve hold the case to its 300 metre rating.