The2Tails Mermaid Tails For Swimming With Monofin by Sparkle Edition Swimmable Mermaid Tails Tail Purchase includes: Monofin, Happy Hats (to protect the tail tips), and FREE Backpack (Pictured)!! Tail assembled and ready to be used. We use a 4-Way stretch, nylon/spandex mix fabric, which creates the perfect fit Our Monofins are 100% reprocessed plastic because we're Mermaids and we care about our our oceans! The monofin is also unbreakable. Made in the USA Please see our size chart for sizing! :)