Four pack of rubber O Rings for use with Sportsheets Strap-ons. Can be used as a cock ring. Materials: Nitrile 70 (NBR) rubber (latex free). Includes: 4 O rings measuring 1.25 inches (3.2 cm), 1.5 inches (3.8 cm), 1.75 inches (4.5 cm), 2 inches (5 cm).