This 3" long cylindrical magnet is world famous! There's one inside every cow! You can do all kinds of cool things with a cow magnet, but cow magnets were originally used as a tool to save the lives of cows, which eat everything from grass and dirt to nails, staples and bits of bailing wire (referred to as tramp iron). A cow has 4 compartments in its stomach, and when these tramp iron items work their way through, they cause all kinds of problems, threatening the surrounding vital organs and causing irritation and inflammation, and worse. When a cow swallows a cow magnet, it lands in the first compartment of the stomach, and attracts the stray metal on its way by, holding it in a safe place.