CMS Magnetics N45 4 x 1 x 1/2" Premium Motorcycle Traffic Light Sensor Magnet, Made of Rare Earth Neodymium Magnet, 1-Count Super strong Neodymium magnet made of licensed material State of the art technology made under ISO 9001 quality systems Can hold up to 109 lbs Accurate dimensions, all the tolerances are +/-0.002" Grade N45, stronger than N42, N40, and N35