Cup magnets are just assembled with magnets and steel cups by using epoxy glue,although they have the simplest structure,but are very widely used. Every shape of inner magnets and steel cups has a specific name. Ferrite countersunk cup magnets are countersunk ring shape feriite magnets with flat steel cup housed.The steel cups well protect the ferrite magnets from broken. Ferrite countersunk cup(pot) magnets are cheaper than neodymium cup magnets,but the magnetic force are weaker,which are only used to hold light and small objects.Please choose ferrite countersunk pot magnets by clicking the link of holding magnets.