This Omega Seamaster Aqua Terra Master Co-Axial is equipped with the watch world’s most advanced mechanical movement, the Seamaster Aqua Terra Master Co-Axial is stylish, sporty and prepared for an active lifestyle.Reference 231.20.39.21.55.003 has a stainless steel & red gold case and bracelet. It is fitted with a mother-of-pearl dial with diamond-set hour markers.