All RK chains are pre-stressed and pre-stretched to ensure equal load distribution and minimal maintenanceThey're made of the highest grade medium carbon alloy steel available, with all components shot-peened and heat-treatedPro X-ring chain lasts five to eight times longer than standard chainProvides two more lubricant pools than conventional O-rings for longer lifeLubricated with specially formulated, vacuum-injected U-grease locked in by tough nitrile butadine rubber X ringsPolished and shot-peened link platesHigh tensile strength ensures reliable performanceIncludes rivet connecting link