Levelling accuracy of 0.2 mm/m. Manual levelling system via two easy to operate adjustment screws. Dual side-by-side laser diodes for an extremely bright, visible beam. Laser can be orientated level or plumb for all common applications. Protected rotary head & side impact roll cage for increased durability. Built-in bump sensor alerts user if laser has been bumped after levelling. Variable speed, 0 - 600 rpm for increased visibility. Wall mount allows the laser to be attached to a wall for drop ceiling installation.