Review on The StudBuddy Magnetic Stud Finder: Locating Studs Made Easy! by Herve Latreche

Simplicity and precision. I just run it along the wall, find some nails and line up the center line of the post. One star off for a non-ergonomic grip that tends to slip out of my hand. If you're curious about the magic inside, it has two 1/2" diameter and 3/8" high, 45mm apart and oriented in the same north/south direction. The actual active length is about 11cm. The two spikes at both ends are just a facade. You can have longer blocks with triple and quadruple magnets for even wider coverage.