Laser class: 2; &lt;1mW<br>Levelling Accuracyt: +/-0.3 mm/m<br>Number of beams: 3<br>Direction of beams: vertical/horizontal/side<br>Indoor Visibility Range: 15 m<br>Self-Levelling Range: +/-4 ø<br>Power Supply: 6.0V – 4 x AA<br>Tripod connection: 1/4″<br>Width: 80 mm<br>Length: 135 mm<br>Height: 145 mm