Durable Ultrasonic Laser Measuring Tool
This is a perfect tool to have when you need to calculate the distance, area, or volume of a room; also has addition and subtraction calculating ability. It's portable and convenient to use. 9V battery - unit of measurement: feet/meters. Accuracy: +/- 0.5% +/- 1cm. Working Frequency: 40kHz. Measures up to 60 feet.