Keychains are usually made of metal or plastic to keep small items like keys on it. Sometimes people attach USB flash drives, carabiners, electronic locks, pocket torches and other small things on it, too.
In the 18th century, they were extremely popular among dandies who slided little trifles of gold, bone or other precious materials on them. Such personalized keychains could fit more than ten items, the number decreased by the mid-19th century by two or three when they served as memorable souvenirs from a family member, for example.
Nowadays, customizable keychains are made specially for you, contain your name, photo, favourite quote or a social network tag, that is, anything you wish. If you have a pet, a cute keychain with its image may be ordered. To get a cool keychain, boldly take goods with guns, skulls, characters from Star Wars or other highly popular film or cartoon, or mind the design.