Specification: Weight: 120g / 4.2oz Measuring range: 50cm ~ 18m Accuracy: 0.5% Resolution: 0.01m Maximum measured distance: 18m Battery: 9V (not included) Reference frequency transmission: 40KHz Degree: ±0.5% Resolution: 0.01m Working temperature: 0℃~50℃ Package list: 1 x Ultrasonic Distance Meter Note: 1. The ultrasonic distance meter measures the distance from the bottom of the machine, not from the top of the obstacle. 2. Try to keep the measuring body perpendicular to the wall, especially when the measured distance is relatively far away. The more vertical the measurement data is, the higher the accuracy. Otherwise, the greater the slope, the greater the error. For long-distance measurements, it is recommended to activate laser positioning to keep it as vertical as possible.