The DEWALT 100 Metre DW03101 Laser Distance Measure calculates area and volume with automatic calculations that make job estimates quick and easy. It has an additional triangular area function. The integrated inclinometer can be used as a digital level to calculate continuous height and indirect horizontal distances. Indirect height measurement uses Pythagoras to measure distances even when point A and/or point B isn’t accessible for linear measurement. The laser distance measure has a large 3-line backlit display which helps to improve screen visibility in both dim and bright conditions. It features a memory unit that stores last 20 measurements. A multifunctional end piece folds at 90 degrees for edge measurements and extends 180 degrees for measurements from corners. Durable design with overmoulded housing, which has been 6 ft (2m) drop tested, and is IP65 water/debris resistant. Specification: Accuracy: ±1mm.Operating Range: 100m (330ft).Power: 2 x 1.5V LR03 (AAA) ;batteries (supplied).