Super neodymium disc magnets with adhesive. No glue is needed, just peel off the adhesive liner and stick to your craft or project (full cure time for adhesive is 24 hours). Industrial strength acrylic foam adhesive conforms to the irregularities or rigid substrates and adheres the magnet to a multitude of materials including wood, plastic, ceramic rock, paper and much more. Due to the extreme strength, these magnets are Not For Children, because they can pinch fingers. More About Neodymium Magnets - All magnets are not created equal. Neodymium magnets are a permanent type of Rare Earth Magnet, made from neodymium, iron, boron and other transition elements. Affordability and availability contribute to this strong magnet's growing popularity. These are the strongest permanent magnets on the market today. Grade N35 offers high performance at an economical price. Neodymium magnets have many uses, from a variety of industrial applications to an unlimited number of personal projects. They can be used in the manufacturing of motors, alternators, and actuators and also great for crafts, school experiments and Diy jobs. Perfect for small yet strong closures and fasteners and ideal for keeping objects secure on any ferrous metal surface.