R-366 Square O-Ring (ID: 7 1/4", CS 3/16", OD 7 5/8"), 2PK The o ring is placed into a groove to secure them in place, and then compressed between two surfaces..
R-325 Square O-Ring (ID: 1 1/2", CS 3/16", OD 1 7/8"), 12PK The o ring is placed into a groove to secure them in place, and then compressed between two surfaces..