The round Knifty Knitter looms are generally used for Knitting hats. The set comes with 4 looms, sizes XL, L, M, and S. The XL loom is for adults. The Large loom is for children's hats. The Medium loom is for babies, infants and dolls. Finally, the Small loom is suitable for mittens and socks.
How to Knit a Hat on a Knifty Knitter loom.