LUMINOX 3581 CHRONOGRAPH WATCHThe 3580 Series introduces several upgraded features designed to weather the toughest obstacles. Whether you're training at the gym or on the job, you will be ready to push yourself to the limit. Function: Chrono, Date Movement: Quartz Size of case diameter: 45mm Case material: CARBONOX Case Bezel: Uni directional rotating Case Back: Screw on caseback Crown: Double Security Gasket Water resistance: 200m 20atm Crystal Glass material: Hardened Mineral