At FIRST4MAGNETS we stock hundreds of different shapes and sizes. Circular disc magnets are incredibly useful and popular and those in this section are no different. Within our 21mm (0.83") diameter range you will find our white, PTFE-coated neodymium disc magnets. They are completely coated in PTFE making them waterproof and ideal for use outdoors, or in applications which will cause the magnet to come into direct contact with liquid.