This button magnet is made of Alnico five magnet material. It is a cylindrical magnet with poles in one plane and has a maximum pull of 10.6 pounds. It has a stability temperature of 1,022℉, a hole diameter of 0.279 inches, and a tap size of 0.31 inches to 0.50 inches. It is made of Alnico five magnet material. It measures 1 1/4 length x 1 1/4 width x 1 height x 1 1/4 inches diameter.