Renthal's R4 SRS Road chain is a specially developed sealed ring chain utilizing Renthal's Self Regulating Seal (SRS) technology to increase the service life of the chain in road applications. The special SRS ring is pre-loaded during assembly creating a spring effect. As the chain wears, conventional O-rings and X-rings lose their seal integrity, whereas the SRS ring is designed to maintain itself during use, keeping a tighter seal against the side plates. This offers increased longevity as the specially formulated grease remains incased around the critical pin and bushing area longer while also keeping dirt, water and other contaminants out. The Renthal "Road R4" chain is supplied with a solid pin rivet link, matching the durability of the chain. SRS ring technology enhances chain flexibility and offers smoother operation than standard O-ring chains.