GLL2-20 Bosch Self-Leveling 360 Degrees Horizontal Cross-Line Laser GLL2-20 Bosch Self-Leveling 360 Degrees Horizontal Cross-Line Laser features four-mode functionality, including single vertical, single horizontal, horizontal/vertical combination and lock/manual modes. GLL2-20 Bosch Self-Leveling 360 Degrees Horizontal Cross-Line Laser has a 360° coverage that gives the user one setup point for an entire room and has a range of up to 65ft. diameter with accuracy of +/- 3/16in at 30ft. GLL2-20 Bosch Self-Leveling 360 Degrees Horizontal Cross-Line Laser features Smart Pendulum System self-leveling function and an indication for an out-of-level condition and a lock that protects the unit for safe transport.