Check the listing for details. Magnet Source Stud Magnet 07612 4 in X 1 in Magnetic Stud Finder 7612. Condition: New. Listed at 19.99 USD. Locate drywall screws and nails in studs, and use as a nail starter and for a plumb line. Ideal for the do-it-yourselfer or home improvement customer who needs to hang pictures, shelves or decorations, or anchor items to a stud. Easy to use, has no mechanical parts, and requires no batteries or calibration. The patented Stud Magnet has a Magnetic Shield which blocks the magnetism when it is not in use. Non-scratch surface is safe for all wall types. All magnets are not created equal. Neodymium magnets are a permanent type of Rare Earth Magnet, made from neodymium, iron, boron and other transition elements. Affordability & availability contribute to this strong magnet's growing popularity. These are the strongest permanent magnets on the market today.