Neodymium magnets are one of the most extensively used rare-earth magnets. They are permanent magnets that are made from neodymium alloy, boron and iron to form a tetragonal crystalline structure. Irreversible means that they have the ability to maintain the magnetic properties over high time periods continuously creating electromagnetic field from their environments.  Neodymium magnets can be found in audio devices, such as audio speakers too. These magnets are made use of in various kinds of restorative devices.  Typically, they are used in several door catches.   Visit https://www.mashimagnets.com/productsd-21-30-59.html