These magnets are 21mm in size & come in sets of 4, 5, 6, or 10. These magnets are medium sized. Please refer to the pictures & measurements above to make sure they are the perfect size for you. Each magnet can hold about 2-3 pieces of paper on its own, but can hold a larger amount the more magnets you add for support. Please note these magnets are not toys & should never be used by children without supervision. Cat Magnet, Glitter Girly Cute Pretty Fridge Dorm Room Decor, Office Supply, Gift For Lover