This is a set of 20 cultural brads (split pins) for use with cardboard. 【Convenient Fasteners】 These pins are ideal as fasteners for securely closing boxes. They are especially useful for packing and storage. 【How to Use】 You cannot insert them directly into cardboard. Make a small hole with something like an ice pick. Be careful, as the brad will become loose if the hole is too large. Once you've inserted the brad, tap the tips of the brad from the back with a hammer. Thank you for viewing.