Made of highly flexible material and TUSA Flex blade material. Even if you are not confident in your leg, you can create stable propulsion. Recommended for those who want to swim long distances with light force on the water; Plastic fins in the world won the Good Design Department Award for the Good Design Department of Health Awards; Size compatible (boot size) SF-5500 (small size) 8.7 - 10.2 inches (22 - 26 cm), External dimensions: 22.4 x 8.5 inches (56 inches (5 inches (5 inches (568 x 214 mm)