The StudBuddy is the world's simplest stud finder, designed to locate wood and metal studs in drywall or plasterboard stud walls. It requires no batteries and conveniently hangs on the wall once a stud is found. This tool is perfect for accurately hanging shelves, cabinets, paintings, mirrors, flat-screen televisions, and other heavy objects. Made in the USA with extra-strong neodymium magnets, over 2 million have been sold.