Directs beams at right angles for perfect placement. Three square 90° beams provide simultaneous level (horizontal) and plumb (vertical) reference points. Also features a built-in bubble level for fast and simple leveling to install shelving, light fixtures, wallpaper, tile, pictures, cabinets, crown molding, and more. Convenient, hands-free mounting options with ergonomic, easy-grip handle. Requires one 9-volt battery (not included).