I chose size 6-12 months for longer wear and the foot part was a bit big and the ankle part was too tight. They left blisters on my daughter's feet in the form of dots holding socks. The first two shots are the first day of the blister, the third is the next day. The last two photos were taken 8 days after wearing, her skin is still not back to normal. I will say that she has sensitive skin/eczema but this has never happened before. She gets pink eczema on her cheeks if I don't put lotion on her and sometimes she gets a little rash in the crease, nothing like that sock rash. but at what cost.