O-rings are circular-shaped gaskets that form tight seals between two objects to prevent liquids or gases from leaking. Backup O-rings install in front of, in back of, or on both sides of the primary O-ring. They provide added protection and ensure no liquids or gases will escape. O-ring splicing kits contain lengths of cord stock and tools needed to create custom-sized O-rings and replace or repair existing ones. Cord stock is available in different materials and lengths and can be cut to create custom-sized seals to replace worn or damaged O-rings.