The powerful magnetic force is only concentrated at the bottom, The other three sides are Protected by steel cups that almost no magnetic force Ni+Cu+Ni Triple Layer Coated. The Best Coating Available, which Provides a Shiny and Rust Resistant Coated steel cup provides protection for the magnet and helps to prevent chipping or cracking Unique design with Countersunk Hole and Eyebolt Great for salvaged of various iron-containning nickel material underwater and Good idea for magnet fishing, lifting, hanging, retrieving applications Material: NdFeB magnet + A3 steel + 304 stainless steel