A bobby pin (also known as a kirby grip or hair grip in the United Kingdom) is a type of hairpin, usually of metal or plastic, used in coiffure to hold hair in place. It is a small double-pronged hair pin or clip that slides into hair with the prongs open and then the flexible prongs close over the hair to hold it in place. They are typically plain and unobtrusively colored, but some are elaborately decorated or jeweled. Bobby pins became popular in the 1920s to hold the new bobbed hairstyles.