1 1/8" diameter. Black machined aluminum housing. Provides accurate, hands-free land navigation in the most demanding conditions. When light conditions become dark, the 10¡ graduations become luminous, making the compass face easy to read. Accuracy +/- 40 mils. Operates flawlessly in temperatures ranging from -50¡ F to 150¡ F. Induction damping for quick needle stabilization. Maintenance-free illumination for over 10 years. Heavy-duty black nylon wristband. Water-resistant. Bulk packed