Omega gents seamaster diver 300m co axial chronograph 415 mmcaliber omega 3330 self winding chronograph with column wheel mechanism and co axial escapement for greater precision stability and durability of the movement free sprung balance equipped with si14 silicon balance spring officially certified chronometerpower reserve 52 hourscrystal domed scratch resistant sapphire crystal with anti reflective treatment on both sidescase steeldial bluewater resistance 30 bar 300 metres