Specification: Weight: 120g / 4.2oz Measuring Range: 50cm ~ 18m Accuracy: 0.5% Resolution: 0.01m Maximum Measured Distance: 18m Battery: 9V (not included) Transmission Frequency: 40kHz Degree: ±0.5% Resolution: 0.01m Working Temperature: 0℃ ~ 50℃ Package List: 1 x Ultrasonic Rangefinder Note: 1. The ultrasonic rangefinder measures distance from the bottom of the machine rather than the top of the obstacle. 2. Try to keep the measuring body perpendicular to the wall, especially when the measured distance is relatively far. The more vertical the measurement data, the higher the accuracy; otherwise, the greater the slope, the greater the error. For long-distance measurements, it is recommended to turn on laser positioning to maintain the most vertical position possible.