Retrieval And Metal Testing Magnet. Small and very powerful. We have mounted a powerful 1/2" diameter x 1/2" tall cylinder N52 grade neodymium-iron-boron magnet in a brass case for industrial and hobby use. It comes with an extra heavy duty split ring for attaching a hook, rope, wire, or fishing line. Here are some possible uses:Perfect for Geocaching.Identify and sort steel grades and metal alloys that contain iron or cobalt.Identify/sort chrome plated items from polished aluminum, silver, and non-magnetic grades of stainless steelIdentify/sort solid brass and bronze from plated steel items (handy in the antique market and hardware store)Identify/sort some types of costume (fake) jewelry, which often uses steel as the base material under the plating.Attach to your fishing line and cast away. You will find all sorts of sunken goodies. I am told that if you live in a big city, bridges are an excellent place to go "magnet fishing." If you want to retrieve really big items (like engine blocks), use this magnet as an underwater finder, when it latches on to something, you can drop a very large normal magnet and pull up as much as you or your boat winch will lift. Also handy for science experiments involving ferromagnetismThe magnet insert is rated at 18 lbs (as with all magnets, this rating depends on the magnet mating to a smooth, flat, unpainted steel surface). It holds a 13 lb sledge hammer with rough and rounded edges in mid air with no problems. The brass casing protects the magnet from chipping and breaking, and makes removing iron and steel shavings much easier. A tight fitting vinyl cap is also included to protect the magnet when it is not in use. This also helps keep the magnet from attracting iron dust and steel chips, as well as offering a little buffer to the magnet"s strength when it is not being used. Caution: do not store this magnet near cell phones and credit cards. These are made in the USA.