1 .Square Laser Level 2. Square accuracy: +-0.5mm/m 3. Power: 3xAA alkaline batteries Five highly focused self-leveling laser beams provide accuracy of 3/8"-in at 100 feet. Tough on the jobsite. Resists water, dirt and dust (IP54)Use to: Plumb and Align: Walls, Doors, Frames, Stud Beams, Windows and Skylights; Level Electrical Outlets; Stud and Curtain Wall Plumbing, HVAC, Plumbing, Pipe ...