A video review of the CH Hanson Magnetic Stud Finder.
This is a very compact and low-cost product that can locate the stud by scanning the screws, nails or steel steel and attracting to it. I find the results are quite accurate.
There are no batteries or electrical led to read and no false positives.
The is also a level and plumb feature to guide for the best spot.
It uses Rare Earth magnets to accomplish this task.