The Bosch GLL 55 professional self-levelling 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 levelling 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 11/8 inch 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.