Neodymium magnet assembly with attached key ring is super powerful. Use to hang keys or attach to a rope/chain with signage for warehouses or stores. Includes non-scratch liner. 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 & availability contribute to this strong magnet's growing popularity. These are the strongest permanent magnets on the market today. 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.