PRINCIPLE-- Ultrasonic range finder uses the ultrasonic wave to the object to be measured, and then calculates the ultrasonic round trip time to determine the measured distance EASY&CONVENIENT-- Handheld laser range finder, small size and easy to carry MEASURING DISTANCE-- The tools needed to quickly measure room and room area. Ultrasonic range finder can measure linear distances from 0.5M to 18M (1.5 feet - 60 feet) TECHNOLOGY-- The range finder uses laser technology to accurately sense and accurately measure distances WIDE APPLICATION-- Measure current temperature, measure length, measure area, measure volume. Suitable for quick measurement of distance and surrounding area wear, home renovation, tools for quick measurement of room and room area Specification: Item Type: Range Finder Measuring range: 0.5m to 18m Maximum measuring distance: 18 meters The sum of the maximum distances: 180.00 meters Maximum calculation volume: 1800.0 cubic meters Battery type: 1 x 9V Battery(not included) Resolution: 0.01 meters Operating frequency: 40kHz Operating temperature: 0-50 Weight: Approx. 105g Package List: 1 Range Finder 1 User Manual