Day or night, the Cammenga Phosphorescent Wrist Compass is always ready to provide accurate, hands-free land navigation in the most demanding conditions. When light conditions become dark, the 10deg graduations become luminous, making the compass face easy to read. FeaturesMachined aluminum casing for durability.Accuracy +/- 40 mils.Operates flawlessly in temperatures ranging from -50deg F to 150deg F.Induction damping for quick needle stabilization.Maintenance-free illumination for over 10 years.Heavy-duty nylon wristband.Water-resistant.