A ring magnetic disc is a basic magnetic disc with a hole which is the same width through the entire magnetic disc. It can be used to attach the magnetic disc to another item.
Ring magnetic discs can be used in many different applications such as furniture, security and fishing for ferromagnetic materials in a river.
Ring magnetic discs are placed in magnetic recessed contacts which are used within a security system to indicate whether a door or window is open or closed.
The security system does this by completing an electrical circuit with the help of the magnet, if the magnets are separated, the circuit is broken and an alarm will sound.