The first diving watch to meet the pressure challenge with the helium release valve, this DOXA Sub 1500T Aquamarine Automatic Men\'s Watch boasts an impressive 1500m water resistance. At A Glance Presented on a stainless steel bracelet 45mm case size with 1500m water resistance Aquamarine dial with unidirectional rotating bezel and integrated helium relief valve Black baton hour markers with Super LumiNova and date window at 3 o\'clock Scratch-resistant sapphire crystal with an anti-reflective treatment Powered by a three-hand self-winding automatic movement with COSC Certified Chronometer Power reserve of up to 38 hours