The BOSCH Self-leveling Crossbeam Laser Leveler offers a range of up to 50 feet. It works by cross-beam projection, one in the horizontal plane and one in the vertical plane. The horizontal level is accurate to 5/16 inch at 30 feet. The instrument has a compact and ergonomic design, as well as IP55 water and dust resistance, providing comfort and reliability in use. The Smart Pendulum System allows the tool to level itself automatically, reporting unevenness with a flashing light and locks when turned off for safe transportation. The unit can be operated either with the included AA batteries or with a Bosch 3.7V 1.0Ah lithium-ion battery (sold separately).