From the single ferrite magnet to this neodymium miracle of strength: ordinary magnets are fine for attaching blueprints, memoranda or recipes to metal doors, fridges or our special magnetic boards. But – what about heavier weights? This is where you need neodymium magnets.
These magnets are extremely powerful and must absolutely not come within range of a pacemaker! The same applies to magnetic data banks, mechanical clocks or compasses. Make sure they don't collide, especially from a distance – they might splinter.