Whoever thought of these sleeves on this particular sleeping bag has no idea about children or design. First, these sleeves have no padding; they are just a simple thin fabric. Second, they are extremely tight; they didn't consider that the child might be wearing something underneath the sleeping bag, which is a fact that is mandatory given how thin they are. I got size 4-5, my daughter is not even 3 years old, and while it fits her well otherwise, I am afraid I will break her arms to get her to wear these sleeves.