Dianoo Adjustable Swimmable Mermaid Tail - Mermaid Swim Fin Siamese Flippers for Girls and Boys It keeps a balanced dolphin kick Soft strap comfortable Adjustable swimming fins. Increasing water confidence and quick release foot strap. Fits shoe sizes boys1-6T, girls 2-8T, suitable most of kids. It comes with a comfortable TPR foot pocket and uses a quick-release foot strap so that feet can quickly be removed from the fin for safety.