LCD BACKLIGHT AND MUTE SETTING - Large backlight screen provides you with a better visibility in dark areas; Mute setting allows you turn on or off the measure beep at your will, suitable for using in library, classroom and other quite places MULTIPLE MEASUREMENT FEATURES - Area, distance, length, volume, continuous measurement, Pythagorean method-three points; Addition and subtraction; Low battery indication; 20 groups data memory; Manually delete data; Auto shut down after 150s without anyoperation to save power DURABLE AND HANDY - IP54 waterproof level and dust-proof function protect the laser distance measure to the maximum extent; Portable size and hard rubber body provide a good grip; Wrist strap lets you hold the meter steady and carry easily