Review on Studpop® 100480 SP Studpop Magnetic Finder by Brian Shakey

The idea of this sounded good and it was cheap so I bought it. And it works as described, but the magnet is so weak that the pin can only be found directly above the nail. Move it half an inch in any direction and it will disappear. Electronic spike finders are notorious for being sloppy, but at least you can make a run through anywhere on the wall and expect to find a spike. Unless you actually see a nailhead at Studpop, it's sheer luck whether you find a bobby pin or not. (And if you see the head of a nail, you already know where the bolt is.)