The hand bearing compass measures 1 3/16" x 3 3/16" diameter and weighs less than 1 lb. This Hand Bearing Compass is accurate, durable and easy to use day or night. The colorful sturdy rubber housing protects the compass and makes it easy to find when needed. This versatile hand bearing compass features superior damping that gives quick and highly accurate readings to within 1 degree. The infinity prism delivers in-focus compass readings. Using the object instead of a lubber line makes readings easier and more accurate. Photo luminescent card provides battery free illumination. A protective rubber collar with neck/wrist lanyard ensures safe use in challenging environment. This compass also works at high altitudes.