I wasn't quite sure how this would work. Took my niece to the pool and watched her try to swim. She can, it's a little all over the place, but she does it. Took the leg float and positioned it between thighs and knees. After several attempts of her getting used to the device, low and behold her swimming improved. It worked by helping her keep her legs in position. Needless to say she went home with it. Her mom said she is sharing with her friends at school and they all like it and some want them. Impressed with this leg float training aid.