Measure, add, multiply, and compute the square and cubic footage of one room or a whole house with just the press of a button. Narrow beam of sound waves “bounce” off solid objects back to the hand held receiver. Custom electronics and a microprocessor convert elapsed time into a distance measurement and display it on the LCD. Computes and adds both area and volume. Adds linear measurements, areas and volumes. Measures from 1’, 6" up to 45’. Features automatic internal temperature compensation, auto-shut-off, low battery warning, and tracking/validate modes. Measures in feet/inches and meters/centimeters. Accuracy is 99.5% plus or minus ¼". Comes with instruction pamphlet and quick reference instruction label on back of unit, in English, French, and Spanish. Requires one 9-volt battery.