Neodymium magnets are made from an alloy of neodymium (Nd), iron (Fe) and boron (B). They are currently the strongest type of permanent magnet available at up to 52MGOe, and can replace Alnico and Ceramic magnets. They have poor corrosion resistance, thus most are coated with a Nickel-Copper-Nickel plating. Various pole configurations may be used.