Eclipse Magnetics E691 Neodymium Rare Earth Shallow Pot Magnet, 200 lb of Pull Force, 2.62" Diameter x 1" Thickness Nickel plated steel pot with neodymium (rare earth) magnet, supplied threaded loop Neodymium magnets are the strongest magnets available; the metal pot helps to contain the neodymium magnetic material Operate at a relatively low operating temperature (120 degrees C) vs alnico and ceramic magnets 200 pounds of pull force 2.62-inch diameter x 1-inch height