A SIGNET ring is a type of ring that is typically used as a seal to authenticate documents. It usually has a flat bezel with an engraved design or initials. A pinkie ring is a small ring worn on the little finger of the left hand. A decoder ring is a type of ring that contains a cipher, which is used to decode secret messages. Teething rings are rings made of rubber or plastic that are designed to help babies with teething pain. An ONION ring is a type of deep-fried snack food made from sliced onions that are dipped in batter and then fried. PRIZE rings are rings given as awards for competitions or achievements. Finally, a piston ring is a metal split ring that fits into a groove on the outer diameter of a piston in an internal combustion engine.