The 12-inch polystyrene level ruler by Mayes is both a level and a ruler, with plumb and level vials (accurate to 0.001 inch). Made of lightweight and durable high-impact composite polymer (just over 0.38" thick), it has easy-to-read numbers and tapered ruled edges for closer measurement. Use the center-finding edge to hang pictures, shelves, and more, center it, then check for level. The compact size makes it easy to take anywhere.