Lensatic Map Mirror Compass LIQUID FILLED- having liquid surrounding the needle helps to steady it. This leads to more accurate readings. ROTATING BEZEL RING- this ring has degree marks from 0-360 with 1 degree intervals. SIGHTING MIRROR- leads to more precise readings. Having the mirror partially open allows you to sight through the notch at the top while looking at your bearings. This can help you set your sights on a distant landmark. This mirror can also be used as an emergency SIGNAL mirror. PROTECTIVE CASE- a fold over protective case keeps the mirror and compass from getting damaged. OTHER KEY FEATURES- this compass consists of a millimeter and inch ruler, map scales, magnifying lens, and easy to read markings