DEWALT DW03050 50 Metre Laser Distance Measure 50M calculates area and volume with automatic calculations that make job estimates quick and easy. Indirect height measurement uses Pythagoras to measure distances even when point A and/or point B isnÕt accessible for linear measurement. The laser distance measure features a memory unit that stores the last 5 measurements, and a 2-Line backlit display helps improve screen visibility in both dim and bright conditions. It has a durable design with over-molded housing, which has been 6 ft (2m) drop tested, and is IP65 water/debris resistant. Specification Accuracy: ±1.5mm.Operating Range: 50m (165ft).Power Supply: 2 x 1.5 Volt LR03 (AAA-size) Batteries (supplied).