About This Watch: This Omega Constellation Co-Axial Watch 123.55.31.20.51.001 has an automatic movement with a co-axial escapement feature. It features a black dial and a scratch resistant sapphire crystal. It is decorated with flawless ideal cut natural diamonds on its face and bezel. Its finely crafted case is made out of 18K white gold. This watch is water resistant up to 10 atm; 100 meters; 330 feet.