PACKAGE INCLUDES:10 mm in diameter, the lower part is approx. 7 mm in diameter and the height is approx 7 mm. 30 pieces locking pin back, enough for your daily use and replacementPINS KEEPERS:It can replace broken screws or locking devices on your brooches, badges, etc, so you can use them again instead of having to choose to discard them HIGH QUALITY:The rear lock of the pin is made of high - quality copper and coated with a silver coating to make the protective plug firm and not easy to rust, durable and long - lasting to useHIGH QUALITY:The rear lock of the pin is made of high - quality copper and coated with a silver coating to make the protective plug firm and not easy to rust, durable and long - lasting to useNO TOOLS REQUIRED:The pin badge locking backs are easy to use, very convenient, as they do not require tools. Simply push the base to lock it in place or pull the base to pull out the badgeMULTIFUNCTION:The pin lock is suitable for pins, badges, jewelry making, DIY crafts, name tags, display books, lanyards, bags, vests, hats, badges, collectibles, etc