Our Neoprene Rain/Snow Boots are lined with 5mm Neoprene and include built-in handles making it super easy for kiddos to pull on and off. Our new Rain Boot sizes run similar to other boot sizes, which usually run big. If your child wears a size 12 shoe, they will likely wear a size 11 in OAKI Neoprene boots. Please see our Size Guide for product measurements.