Official U.S. Military Issue. Model #J582T. Lightweight and accurate! Provides easy on-the-go referencing for land navigation day or night. Machined aluminum casing for durability. Easy to read 10° phosphorescent markings are enhanced with Tritium for visibility in total darkness. 12 year Tritium life. Includes nylon wristband. Temperature range -25°F to 125°F. MADE IN USA.