This is a 12mm diameter ceramic ferrite magnet, round shape, 4mm thickness, with high cost performance and good magnetic strength, suitable for electronics, toys, office supplies, sensors, etc., similar close to the size of 12x3mm, 12x5mm, welcome to inquire about bulk price.
Note: We are a manufacturer of permanent magnets, for round magnets, you can do chamfering, scribing, denting and other ways to facilitate you to distinguish between NS poles, some users need plating, painting and so on are available.
Those who only need 12mm but require strong magnetism can take a look: