R-364 Square O-Ring (ID: 6 3/4", CS 3/16", OD 7 1/8"), 240PK The o ring is placed into a groove to secure them in place, and then compressed between two surfaces..
R-123 Square O-Ring (ID: 1 3/16", CS 3/32", OD 1 3/8"), 48PK The o ring is placed into a groove to secure them in place, and then compressed between two surfaces..