got these as a gift and was very excited to try them. my daughter wears size 5 shoe and that was the size we're using, but they are extremely difficult to get on her feet. some type of zipper or velcro closure at the back of the foot would have been a great idea. used once, don't know if i'm up for the challenge of getting her feet in them again.
purchased a size small for 16 month old (shoe size 4/5), size medium for a 3.5 yr old (shoe size 8/9). couldn't even get these on their poor little feet! i LOVE this idea, just wish i was able to use them. i will return them to the store.
As a previous reviewer, these got holes in the bottom after one use! Have used them 2 more times and one sock has a hole 1.5" in diameter. They're useless now. LOVE the concept, they just aren't durable enough for regular pool swimming!
Bought S for 2 year old, M for 4 year old. Took these to indoor water park where rubber soled swim shoes not allowed because hazardous on slides (stick to walls). My kids loved them but soles had holes after one day of wear! Very very disappointed. The idea is awesome but not worth money for one wear.