The Cammenga Tritium Wrist Compass is accurate. Hands-free. Tested in the most demanding conditions. Count on the Cammenga Tritium Wrist Compass day or night. Easy-to-read, 10deg graduations - enhanced with Tritium Micro Lights - make it invaluable for on-the-go land navigation. FeaturesMachined aluminum casing for durability.Operates flawlessly in temperatures ranging from -25deg F to 125deg F.Induction damping for quick needle stabilization.Maintenance-free illumination for over 10 years.Heavy-duty nylon wristband.Water-resistant.