R-431 Square O-Ring (ID: 5 1/4", CS 1/4", OD 5 3/4"), 4PK The o ring is placed into a groove to secure them in place, and then compressed between two surfaces..
.R-375 Square O-Ring (ID: 9 1/2", CS 3/16", OD 9 7/8"), 90PK The o ring is placed into a groove to secure them in place, and then compressed between two surfaces.