On the LEVEL magnetic stud finder.Red.Finds metal fasteners holding the wall board to the studs.Two moving magnets provide both an audible click and a visual movement when fastener is found.

I usually use a magnet to find my studs and when I saw this I had to give it a try. The nice things about using this over a normal magnet is that it can detect them even through thicker material like plaster and you know for sure when you find one when it "pops". A nice and simple but effective tool to have in your toolbox.