Marathon JDD WW194021 Swiss Made Military Issue Large Bilingual Diver's Automatic with Day & Date with Tritium MIL-SPEC: Built to Government specifications for use by military personnel. Nato Stock Number 6645-21-886-8975 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. AUTOMATIC MOVEMENT: 26 Jewel Swiss made Sellita SW220 self winding mechanical movement. Submersibility: 30ATM SWISS MADE: Marathon watches are proudly made in La Chaux de Fonds, Switzerland since 1939.