All our hats are an organic Merino/Corridale cross pure New Zealand sheep wool. The wool has been handspun, handknitted and then felted by Carolann. The size of the hat is adjustable by wetting the hat and putting on your head when it is still wet if it is too small. If it is too big then wash in a washing machine and put on your head when it comes out of the machine. This is an adult sized hat. This hat even has organic polka dots and as it is felted it will keep your head warmer than just a knitted wool hat.