This powerful neodymium block magnet measures3/8" in diameter and 1/16" in thickness, with the pull force of 3.45 Kg vertically. The magnet is made from an alloy of neodymium, iron and boron, plated with triple layers of nickel-copper-nickel for effective corrosion protection. The adhesive magnets features 3M adhesive applied to either the north or the south pole.