Square O-Ring (ID:9 mm, CS:2 mm, OD:13 mm), 12PK The o ring is placed into a groove to secure them in place, and then compressed between two surfaces..
.Square O-Ring (ID:16 mm, CS:2 mm, OD:20 mm), 6PK The o ring is placed into a groove to secure them in place, and then compressed between two surfaces.