ProTek is a brand of tritium tactical watches designed for Law Enforcement, Fire Fighters, SWAT, Tactical, Military, Special Forces, and First Responders. ProTek is a no-excuses brand that is Rugged at Heart and built to handle what life demands in any environment, lending credence to the tag line All Terrain Watches. ProTek watches were submitted to the US Marine Corps and were approved as an Official Watch of the USMC based on the accuracy, durability and superior ProGlo illumination that make these ideal timepieces to serve Marines in the line of duty, and in their daily lives. Specifications: 45mm Carbon Composite Case and 60-Click Dive Timing Bezel, 316L Stainless Steel Embossed ScrewSignatureCaseback, Steel Screw Crown with Multiple O-Rings, Sapphire Crystal with Antireflective Coating, Water Resistant to 300 Meters (all watches tested in air and water), Genuine Rubber Strap (22mm x 20mm) with Signature Buckle and a Steel Tube Molded into the Rubber for Additional Durability, with matching colors Used for the Rubber Grip on the Crown, Dependable Japanese Quartz Citizen/Miyota Super 2035 3-Hand & Date Movement with 4-Year Battery, Swiss self-powered ProGlo illumination system. ProGlo illumination system is 100X brighter than conventional lume and glows continuously for 25 years without a need to be "charged" by an external light source. This watch uses the largest tritium tubes available (T100)for the indices in three colors.