Do any of these actually work? Reading reviews it seems to me I might just as well hold up a choc ice and see if it melts.
I just used my rather old detector to trace a mains cable I wanted to use for a wall light. I'm now cut into the wall over 8 cm and nothing is there, despite the damn detector going off when it's over the hole.
Oh, well, it could be worse - I could have drilled through a cable it didn't detect.