The costume runs small. I bought it for my 3 yr old who is just at 3ft and 30lbs, he fits it perfect. There are cuffs around the ankles and wrist to keep air inside, also one for the neck that is not constricting. My only issues is the fan. It comes with a 6v (4AA) battery power source. When I turned it on with my son inside it would not fully inflate. The head kept falling over restricting his view and caused him to keep pushing it out the way. I purchased a 12v dc battery pack online for a couple bucks and rewired it to the existing fan. This caused the suit to inflate to the fullest and solved the problem. Glad I was able to solve the fan issue; would I purchase again, probably.