This is the Momentum M30 Automatic Watch with Scratch-Proof Sapphire Crystal Display Features: The dive watch used by professionals Trusted by military and tactical teams across North America Comes standard with virtually scratch proof sapphire crystal Comfortable 4 o’clock screw-down crown that reduces “wrist-bite” Matte 316L stainless steel case with 300M of water-resistance (yes you read that right) Rugged Japanese Seiko NH35 automatic (self-winding) movement Extremely legible dial with applied SuperLuminova “sharktooth” indices Movement: Japanese, Automatic, Seiko NH35A Dial Color: Black Crown: Screw-down crown Water Resistance (m/ft) : 300 / 1000 DIMENSION: Case Diameter: 44mm Case Height: 15.5mm Lug Width: 22mm Lug-to-Lug: 52.5mm The M30 Automatic introduces the Roto-wind Japanese automatic movement to the Momentum line. It features a display back, 30ATM case, virtually scratch proof sapphire crystal and indexes coated with many layers of high grade luminous paint for optimal luminous performance.