Spectra Precision Laser LL300-2 Automatic Self-leveling Laser Level, 10-Foot Grade Rod and Tripod Kit Increases productivity with fast setups, fewer mechanical parts, and automatic self-leveling Maintains performance even in rainy, dusty and other harsh job site and weather conditions Durable design reduces downtime due to drops and tripod tipovers Minimizes power costs, alkaline batteries packaged standard with kit. Rechargeable batteries available at extra cost The optional RC601 Remote Control gives you the ability to put the laser in manual mode for matching slope applications Class 2 Laser and &lt;3.4mW (less than 3.4 Milliwatts) Laser Source: 650 nm, Class 2, &lt;3,4mW Laser Accuracy: 3/32 in at 100 ft (2.2 mm at 30 m) Operating Range: 1,650 ft (500 m) diameter Self-leveling Range: 5 degrees Compensation Method: Electronic self-leveling Single Axis Manual Slope Mode: Yes (w/self-leveling mode on the second axis), with optional RC601 remote control Out-of-level Warning: Rotor stops, red out-of-level HI-LED flashes Power Source: 4 x D-cell alkaline batteries Battery Life: Alkaline - 90 hours Battery Status LED: Flashing red LED Rotation Speed: 600 RPM Tripod Mount (Horizontal and Vertical): 5/8 x 11 Operating Temperature: -4 F to 122 F (-20 C to 50 C)