Use the RYOBI 25m 360° Green Line Laser for DIY jobs that require precise leveling, alignment or layout in a large room. It projects a single horizontal laser line across all four walls of a room. The horizontal laser line helps you install shelves, picture frames, dado railing and cabinets on walls at the same height—even when they’re on opposite sides of a room. Project the vertical laser line to form a cross line projection. Use this feature when you need square or plumb lines, like when installing tiles. This Green Line Laser’s automatic self-leveling feature with an LED indicator ensures laser lines will automatically self-level within three seconds. The green laser lines can be projected up to 25m and are accurate up to ±0.5mm/m. The Green Line Laser has a ¼” mounting point for securing to tripods and extension poles. Four AA batteries are included for operation straight out of the box.