Omega seamaster aqua terra 150 m omega master co axial 34 mmsteel on steelmovement caliber omega 8520 self winding movement with co axial escapement for greater precision stability and durability resistant to magnetic fields greater than 15 000 gauss free sprung balance system with silicon balance spring automatic winding in both directions to reduce winding time rhodium plated finish with exclusive power reserve 50 hourscrystal domed scratch resistant sapphire crystal with anti refl