Marathon WW194007 Tsar Swiss Made Military Issue Milspec Diver's Quartz Watch with Tritium Illumination MIL-SPEC: Built to Government specifications for use by military personnel. Nato Stock Number 6645-20-001-9382 engraved on case back TRITIUM GAS TUBES: Self illuminating tritium gas tubes glow with no need to be charged by an external light source. SEARCH & RESCUE: Designed for Search And Rescue missions at sea, water resistant to 300 meters (1000 feet) underwater. HIGH TORQUE MOVEMENT: Swiss made ETA F06 3 jewel high-torque Quartz movement with EOL (End-of-Life) indicator for superior timekeeping and quality. Submersibility: 30ATM SWISS MADE: Marathon watches are proudly made in La Chaux de Fonds, Switzerland since 1939.