"DeWalt DW03050-XJ 50M Tool Connect Laser Distance Measurer Metre. FEATURE Laser distance measurer (LDM) manufactured to withstand the inevitable job site drops and falls on the Job site It has a range of up to 50m and an accuracy of +/- 1.5mm Common end-user functions : linear meter readings, surface and volume calculations. It will add or subtract readings and calculate distance in Metric and Imperial. The user can select the unit to continually measure which allows layout applications. Pythagoras indirect height function will allow to measure distances even when point A and/or point B isn’t accessible for linear measurement Unit stores last 5 measurements The unit has large, raised, oversized buttons to avoid miss measures Backlit, 2 line display to provide visibility in all working conditions Will survive a 2m drop onto concrete and has an IP65 water/debris resistance The unit has a flat base that gives a solid platform to measure without the unit shaking and moving to help avoid measuring errors. SPECS: Laser Class: Class 2 Levelling Accuracy: +/- 1.5mm/m Bluetooth Connectivity: Yes Number of beams: 1 Indoor Visibility Range: 50m Power Source: 2 x 1.5v dc LR03 (AAA-size) batteries Weight (incl. battery): 150 g"