0.125" Diameter x 0.125" Thick Neodymium Iron Boron NdFeB Cylinder Magnet, Ni-Cu-Ni 3 layer plated. Nickel-Copper-Nickel triple layer coated for maximum protection and durability. Grade N45, stronger than N42, N40, N38 and N35. Magnetized through the Thickness. Approximate pulling force: 1.5 lbs