In the usual knitting process, the sock is begun at the top and knitted toward the toe. Upon reaching the heel, the machine begins to move more slowly in a semicircular ("reciprocated") fashion to produce the heel pocket. It may be adjusted to reciprocate again at the toe to form a toe pocket. All socks do not have reciprocated toes and heels. For example, the basic tube styles have neither. The "fishmouth" toe closure is non-reciprocated but may be used on a stocking with a reciprocated heel.