Marathon Pilots Navigator Wristwatch w/Tritium Black. The Marathon Military Navigator Pilots was first developed in 1986. It was made as a request by Kelley Air Force Base for a watch which could be used in situations a pilot or parachutist would encounter. Marathon fulfilled this request with the Navigator Pilots Quartz. Made from a special fibershell case that is water resistant to 6 ATM sweat and shock resistant as well as lightweight. Included with the Military Navigator Pilots Quartz is a 20 millimeter width nylon strap made under MIL-S-46383B Type III. The watch uses an acrylic crystal resistant to rapid changes in pressure that would cause a watchs crystal to shatter. The Navigator Pilots Quartz is made in La Chaux de Fonds Switzerland. Powered by a Swiss made high torque 3 jewel ETA F06 Quartz movement as a result the Navigator Pilots Quartz guarantees you a high degree of accuracy in timekeeping. The ETA F06 is accurate to -0.3/+0.5 seconds per day and includes an End of Life (EOL) indicator. The Navigator Pilots Quartz uses self contained Tritium gas tubes to ensure constant visibility in low light situations; therefore a tube is placed on each hour marker hand and at the 12 hour marker in the bezel. Tritium tubes are self illuminating gas tubes which contain an isotope of hydrogen that glows consistently for years. The Navigator Pilots Quartz combines military durability with Swiss craftsmanship in a timepiece that will satisfy you for years. MIL-SPEC: Manufactured in accordance with MIL-PRF-46374G Type III Class 1 US Government Specification. Issued and worn by troops in Iraq and Afghanistan. TRITIUM GAS TUBES: Self illuminated 24/7 tritium gas tubes for up to 25 years. NAVIGATOR PILOT: Designed for pilots and parachute missions. Features fibershell high impact case with stainless steel back. 41mm case size. 13mm thick. Water resistant up to 60 meters or 200 feet. Includes laser cut 20mm nylon straps in black with stainless steel 316L IPD black buckle (optional nylon straps are available. SWISS MADE: Proudly hand made in La Chaux de Fonds Switzerland since 1939. Uses ETA F06 high-torque 3 jewels Quartz movement with EOL (End-of-Life) indicator. Specifications for Marathon Pilots Navigator Wristwatch w/Tritium: Manufacturer: Marathon Application: Flight Parachute Military Gender: Male Dial Color: Black Case Material: High-Impact Fibershell Case Diameter: 41 mm Band/Strap Material: Nylon Wrist Band Type: Strap Movement: ETA Movement F06 Water Resistant Mark: 200 ft Country of Origin: Switzerland Age Group: Adults Package Contents: Marathon Pilots Navigator Wristwatch w/Tritium Marathon WW194001BK-0001: Pilots Navigator Wristwatch w/Tritium Black