Omega gents seamaster planet ocean 600m co axial gmt 435mmcaliber omega 8605 self winding movement with co axial escapement for greater precision stability and durability gmt with time zone function silicon balance spring on free sprung balance 2 barrels mounted in series automatic winding in both directions to reduce winding time rhodium plated balance bridge and oscillating mass luxury finish with exclusive geneva waves in arabesquepower reserve 60 hourscrystal domed scratch resis