Neodymium magnets are the most widely used rare-earth magnet, made from an alloy of neodymium, iron and boron. It was developed independently in 1982 by General Motors who partnered with Sumitomo Special Metals, and these neodymium magnets are the strongest type of permanent magnet commercially available. Since their introduction, they’ve replaced other types of magnets in modern products, like motors in cordless tools, hard disk drives and magnetic fasteners.
In this video demonstration by Magnetic Games, they use various monster neodymium magnets to see what happens when they come close to tiny magnetic balls. The Monolith, a monster magnet with a 200kg adhesive force, is used to attract 2592 magnetic balls, and as you can see, the collision was quite violent to say the least with the shiny spheres splashing everywhere. Fortunately, this person wore protective glasses during every test and it paid off.