R-221 Square O-Ring (ID: 1 7/16", CS 1/8", OD 1 11/16"), 240PK The o ring is placed into a groove to secure them in place, and then compressed between two surfaces..
R-331 Square O-Ring (ID: 2 1/4", CS 3/16", OD 2 5/8"), 16PK The o ring is placed into a groove to secure them in place, and then compressed between two surfaces..