The Dewalt 3 Beam Laser Pointer is a self-leveling unit which is accurate to ±1/4" @ 100'. The Power Lock system features a single lever on off swtich which locks pendulum in the off position for added durability. The unit also features bult in magnetic pivoting brackets that mount easily on metal surfaces, and the integrated track clearance enables users for fast and accurate bottom and top track installation. The focused laser beam keeps dot size small over longer distances for improved accuarcy and visibility indoor visibility range of 100 ft. It also features an overmolded housing which helps to maintain calibration under jobsite conditions. This unit includes a handy kit box, and operates on 4 AA batteries.