R-443 Square O-Ring (ID: 7 1/2", CS 1/4", OD 8"), 6PK The o ring is placed into a groove to secure them in place, and then compressed between two surfaces..
R-217 Square O-Ring (ID: 1 3/16", CS 1/8", OD 1 7/16") (1 Square O-Ring) The o ring is placed into a groove to secure them in place, and then compressed between two surfaces..