Booster swim fins are ideal for swimmers learning to swim. Feedback from Booster fins teaches swimmers how kicking generates forward movement through the water. Made of a natural rubber that floats, Booster fins help lift legs to the surface and teach proper body position. The open-toe design on the underside of the fins prevents feet from chafing and provides the most comfortable fit. Features: Designed to accommodate young swimmers as they transition out of FINIS Fishtail 2 swim fins Open-toe design on the fins' underside prevents chafing and ensures a comfortable fit Promotes extension of legs to develop proper body position Teaches swimmers how kicking generates forward movement through the water Users with wide or high-arched feet may prefer to size up