Mermaid Fins: (Used by teenagers aged 15-20) This mermaid fin is the best helper to make learning swimming more interesting for teenagers. In addition to strengthening the boy's self-confidence in the water, it allows him to practice fish-shaped kicks and body rhythm. High Quality Materials: Our mermaid fins are made of high quality PP+TPR. So the mermaid fins are more durable, super strong and won't break, and the rounded ends protect your fabric wrap. Swim Faster: Soft and strong mermaid fins immediately and significantly increase swimming speed. Even if you are not a professional swimmer, it greatly increases the fun of swimming. Quick On and Off Design: The quick put on and take off design makes the product safer when used in water. Three-channel central blade for optimal water movement during the pedaling cycle. Warning: Mermaid tails or monopods can significantly reduce swimming ability and should only be used by qualified swimmers under the strict and qualified supervision of adults, regardless of swimming ability. Safety Precautions: If used in water, intended for experienced swimmers aged 15 and over. This is not a floating craft and requires adult supervision. Note: The data are all measured manually, please allow 1-3cm error due to light differences and display, there may be color differences, please refer to the actual item received.