High grade N42 (NdFeB) neodymium magnet. Each magnet's north and south pole are on opposite curved sides. Coated with three layers of nickel, copper and nickel to reduce corrosion and provide a smooth and clean finish. Please note: Do not put in moth or nose. These magnets have a very strong holding force, they are not a toy! Extremely versatile: kitchen, office, model making, workshop, assembly, pin board and much more.