Vinyl figure Keychain 4 cm Pocket POP. Pocket Pop keychains are small, portable versions of popular Pop figures that can be attached to keys, bags, or wallets. Despite its small size, Pocket Pop keychains have become a popular part of many fans' collections. These keychains give fans a chance to show off their love for their favorite characters in a simple and practical way, while also being used to identify and organize keys and other small items.