Made of high quality ABS, it is solid, and good performance, long service life. for wireless height ruler for measuring height in 3 seconds, high efficiency. Wide measurement range from 5cm-2m can meets the measurement requirements of the whole family. It automatically turn off after 6 s no operation, energy saving and extend life. LCD display for easily reading. Buzzer operation tips, convenient to operate. No need to install, just lay it flat , one switch operation. Great ruler for recording the growth of your children. Height ruler only, other accessories demo in the picture is not included! Powered by: 3 x AAA battery(Not included) Working current: 30mA Standby current: Less than 20uA Function: Buzzer indicator, 1 button control Display: LCD Accuracy: 0.1cm Colour:Green Material:ABS Package Contents: 1 x Ultrasonic Digital Measuring Instrument Only the above package content, other products are not included. Note: Light reflection and different displays may cause the color of the item in the picture a little different from the real thing. The measurement allowed error is +/- 1-3cm.