Bosch Cross Line Laser, Bare Tool, +/-1/8 in Accuracy, 50 ft Measuring, +/-4° Auto Leveling, 2 Beam, Laser Class: 2, 14 to 22°F, 3 x AA Battery, Plastic Housing Material, 4.4 in L x 2.2 in W x 4.2 in H. The Bosch GLL 55 professional self-leveling cross-line laser features vertical, horizontal and cross-line modes and can project two lines independently or together, for a broad array of alignment and leveling applications. It includes the Bosch exclusive VisiMax™ technology, which allows for outstanding line visibility in standard working conditions. VisiMax constantly monitors the laser's temperature so the diodes are always driven to maximum line brightness, while protecting the laser diodes from overheating. The laser lines are visible up to 50 ft, with an accuracy of /-1/8 in at 33 ft. The Bosch smart pendulum system self-levels and indicates out-of-level condition, to help ensure an accurate layout. It locks the pendulum after the laser is switched off for secure transport. The included magnetic L mount provides strong magnets to attach to steel studs and a free-standing mode with retractable feet. Bosch GLL 55 Cross Line Laser, Bare Tool, +/-1/8 in Accuracy, 50 ft Measuring, +/-4° Auto Leveling, 2 Beam, Laser Class: 2