The Renthal C291 R3-2 O-ring 520-Pitch 114-Links Chain includes Nitrile ‘O’ rings to extend the chain’s life. The rings retain the unique vacuum-injected grease that is injected inside each joint of the chain. The chain is created using shot-peened alloy steel sides plates, giving it maximum impact load resistance and high tensile strength. Wear resistance is further increased by the use of high carbon alloy steel bearing pins, while corrosion is prevented by the gold-colored side plates. The chain is pre-stretched to enhance its performance.