R-439 Square O-Ring (ID: 6 1/2", CS 1/4", OD 7"), 4PK The o ring is placed into a groove to secure them in place, and then compressed between two surfaces..
R-132 Square O-Ring (ID: 1 3/4", CS 3/32", OD 1 15/16"), 90PK The o ring is placed into a groove to secure them in place, and then compressed between two surfaces..
.R-357 Square O-Ring (ID: 5 1/2", CS 3/16", OD 5 7/8") (1 Square O-Ring) The o ring is placed into a groove to secure them in place, and then compressed between two surfaces.