-The 520SO is one of the best O-ring chains in the industry-520SO chains feature heat treated hi-carbon alloy steel components with seamless rollers and shouldered bushings for strength and durability, and are fitted with O-ring seals-O-ring seals ar..
-Natural Steel Finish Clip Type Connecting Link for RK 520SO O-Ring Chains-O-ring seals are made from an advanced Nitrile Butadiene composite for maximum performance and wear life-Nitrile Butadiene O-rings seal in lubrication and deliver smooth power..