The Stabila LD 250BT Laser Distancer is a compact, easy-to-use laser with 4 measuring functions: length, area, volume and continuous measurement. It has a large, back lit screen with large readout making it easy to read in any enviroment. With an impact-resistant, IP54 rated housing with shock-absorbent soft-grip casing. Integrated Bluetooth® Smart 4.0 technology enables measurement data to be wirelessly transferred from the laser to a smartphone or tablet. The free 'Stabila Measures' App allows measurements to be transferred directly to photos of the building site or drawings. It delivers quick measurement results and assists in daily work, e.g. calculating how much material is needed. Specification Accuracy: ±2.0mm.Operating Range: 0.2-50m.Power Supply: 2 x AAA Batteries (Included).Protection Class: IP54 (dust & water splash).Laser Class: 2.Laser wavelength: 635nm.