The body of these mitts are knitted, with crochet around the top, bottom, and thumb. They were felted once, and were so small when I got them out of the washer I had to work really hard at getting them on. I left them on wet all day and even slept with them on that night. They fit perfectly now. The crochet band at the wrist increases and bells out. My sweater sleeves fit in there without assistance from me and it forms a seal no cold weather seems to be able to penetrate.