Ultrasonic signal measures distances with an accuracy of ±.05%. Built-in laser pointer provides a sight line for aiming at target. Multi-functional measurement buttons for storing and calculating~area and volume as well as adding and subtracting combined measurements. Converts between metric and standard readings. Large~digital LCD screen. Ideal for measuring square footage for floor and wall coverings and room volumes for heating and cooling. Requires one 9 volt battery (not included).