This versatile tool has multiple applications across several different hobbies and activities. It folds for easy storage, and takes the guess work out of alignment, measuring and placement on your projects. The Laser Square has inch and metric measurements and can be adjusted to a 90 degree angle or placed together in a straight line. The laser slides from 0 to 12 inches (0 to 30.5 cm). Use with the Laser Square Trimmer (660509) for precise cutting, perforating or scoring; sold separately. Requires two 9V batteries; not included.