Xiongyi Kids Girl Swimwear Top Panties Mermaid Tail 3Pcs Swimming Costumes with Mono Fin 100% Polyester Kids Girls Swimsuit Kids Swimming Mono Fin Children Swimming Costumes The Mermaid tails Material is polyester,the Mono fin Material is TPR+PP if you have any problems with the products,please feel free to contact me back,then i can resolve the problems for you soon.