Super Strong N50 Rare Earth Neodymium Magnets, stronger than N48, N45, N42, N40 N38 and N35 * Extremely durable Epoxy + Copper + Nickel 3 Layer Coated with tapered center hole. * Tapered counter sunk center hole on both sides of magnet to recess a screw head. * 0.14" diameter counter sunk center hole works with #6 screws. * 1 magnet per package. Pull Force: over 89 lbs, Great performance, Wholesale Price