Stanley Intelli Tools Ultrasonic Distance Estimator
The Stanley Intellimeasure 77-018 Ultrasonic Distance Estimator measures distances up to 12m/40ft at ±0.5% accuracy with an easy to read LCD screen.
It calculates area, estimates materials for flooring, painting, wallpapering etc. and volume. It estimates heating/cooling requirements. It displays the last 3 measurements (no data retrieving necessary), measures in metric and imperial units and is able to toggle between linear, area and volume modes.
Requires a 9V battery (not included).