This do not fit regular or older Barbies. I think they may be Disney gowns.  But no sure.  They both have Velcro closures.  Please see all photos and the length next to the ruler.   There are no tags but in good condition.  Ask questions prior to bidding or buying.  

These Disney Princess Fashion Doll Dresses are a set of two multicolor long gowns designed for 9" - 11" girl dolls. Made of cloth material, these original Disney branded dresses are suitable for all occasions and are part of the Disney product line. The set does not include any tags and is perfect for adding a touch of magic to any doll collection. Made in China, these doll dresses are sure to enchant and delight any child or collector of Disney-themed accessories.