How many times have you driven a nail or screw into a wire behind a wall. Well, I dont know about you, but I certainly have Especially those long drywall screws that love to cut right through a chunk of romex cable. Been there, done that

This detector kit will let you easily search for wires inside or behind walls, as well as track down interruptions. Simply hold the device around the area you wish to check and the LED will begin to flash when it gets near a wire with supply voltage. The faster the flashing, the closer you are to the wire. If you would prefer an audible cue, the kit is built to work with an optional PC mounted buzzer as well (SV412S). Board measures 2.2 x 2.5. From Velleman. (Yes, the wall was just finished, and it was a 220V line for a baseboard heater, and yes, had to open up the wall)