Kids Finz help young swimmers learn a proper horizontal body position and gain confidence in the water. Made out of a soft polyvinyl material, Kids Finz offer little swimmers comfort and flexibility. The fins come with an adjustable heel strap that makes it easy to put the fins on and off. The Kids Finz come in 2 sizes, Toddler Yellow (shoe size K 5-11) and Child Blue (shoe size K 11-2). Replacement heel straps are sold separately.