Make a statement with our Limited Edition Designer PONY 2.O! The diameter is the same as the PONY-O, but the 2.O is slimmer and designed to hold sections of the hair. You can also wear it for a less perky ponytail, if your hair is super fine, or use it in place of damaging and uncomfortable elastics in children's hair. Comfortable, secure, non damaging and no annoying ponytail crease! Designed to last hundreds of uses. Classic for Super Fine, Normal, Slightly Thick Hair XL for Really Long, Super Thick, Extra Heavy Hair!