Bought the small size for my 35 pound son. Fits fine, but doesn't keep him afloat very well. The suit is just has a foam pad on the chest and one on the back. In the water is floats up towards his face. Overall, it is pretty bulky and leaves him pretty unstable.

My son loves his floating swim suit . It is easy for him to put on and use . It is easier to find this type of thing on the internet and purchase than to drive all around .