Zircon StudSensor i60 Center-Finding Stud Finder with DVD How-To Guide Locates the edges and center of wood or metal studs up to 1-1/2-Inch (38 mm) deep Easy-to-read LED display, audio tone, and the patented SpotLite Pointing System indicate stud center Wire Warning detection indicates the presence of live, unshielded electrical wiring up to 2-Inch (51 mm) deep Built-in erasable marker makes one-handed operation easy Have questions? Need more information? Call the Zircon Customer Service department at 1-800-245-9265, Monday-Friday 9am - 5pm PST. We'll be happy to help!