AOMAG Alnico Magnets featuring aluminum, nickel, and cobal alloy are built for heavy duty use and will not naturally demagnetize over time Hole in top of magnetic for attaching conveyors, racks, and welding jigs The strong magnetic pull of these horseshoe power alnico magnets makes it perfect for lifting, holding, sorting, clamping or retrieving steel or iron parts Red horseshoe magnets with keeper to retain magnetic power. Ideal for school experiments Pull Force: 20 lb, Width: 1.18", Height: 0.78", Depth: 0.78", Space Between Poles: 0.59“ Magnets Alnico Horseshoe Magnet with Keeper,Red Cast Horseshoe Heavy-Duty Alnico Power Magnets for Education