HIGH ACCURACY - With laser precision technology, accuracy up to ±0.3-100M with a measuring accuracy of ±1.5mm, the measuring distance extends up to 50m; Switchable between M/In/Ft for free adjustment. With 2 unique bubble levels that allow more accurate measurement compared to one bubble. LCD BACKLIGHT & SILENCER ADJUSTMENT - The large backlit display gives you better visibility in dark areas. With the mute function, you can turn the acoustic signal on or off as you like. Suitable for use in libraries, classrooms and other quiet places. MULTIPLE MEASURING FUNCTIONS - Area, Distance, Length, Volume, Continuous Measurement, Pythagorean Method - Three Points; Addition and Subtraction; Low Battery Indicator; 99 Groups of Data Storage; Delete Data Manually; Automatic shutdown after 150 seconds without operation to save electricity. DURABLE AND PRACTICAL - IP54 waterproof and dustproof function protects the laser distance meter to the greatest extent. Portable size and hard rubber body