The RYOBI Whole Stud Detector is designed with multiple LED's to indicate the full width of the stud, not just an edge or center. The one-handed operation provides an easy to use experience every time. The Auto Depth Scan Technology determines the thickness of the wall up to 1-1/2" thick to accurately identify wood and metal studs. The built-in stud marker conveniently marks the center of the stud without the need for a pencil. Included is (1) Whole Stud Detector, (2) AAA Batteries and Operator's Manual.