Metal Detector is a device to locate hidden metal parts, pipes and electrical conductors on land and under water, usually has a electronic circuit and a coil.
Where to Go Metal Detecting With Your New Metal Detector! - Tips Field Guides
I am not sure where This would be something you're want to wear, but I'd love to try explaining this after a metal detector.
Homemade metal detector made with a calculator and an AM/FM radio.
Gift Ideas for Boys ~ This Bounty Hunter Junior Metal Detector gets lots of great reviews, and I’m all for anything that get the kids outside more often.
Sneakier uses for everyday things : how to turn a calculator into a metal detector, carry a survival kit in a shoestring, make a gas mask with a balloon, turn dishwashing liquid into a copy machine, convert a styrofoam cup into a speaker, and make a spy gadget jacket with everyday things / Cy Tymony.