R-437 Square O-Ring (ID: 6", CS 1/4", OD 6 1/2"), 4PK The o ring is placed into a groove to secure them in place, and then compressed between two surfaces..
R-235 Square O-Ring (ID: 3 1/8", CS 1/8", OD 3 3/8"), 36PK The o ring is placed into a groove to secure them in place, and then compressed between two surfaces..
.R-149 Square O-Ring (ID: 2 13/16", CS 3/32", OD 3"), 20PK The o ring is placed into a groove to secure them in place, and then compressed between two surfaces.