RK Racing Chain GB520MXZ4-140 Gold 140-Links Heavy Duty Chain with Connecting Link GB520MXZ chains are made for the serious motocross racer looking for the lightest, strongest non O-ring chain GB520MXZ chains feature chrome-moly steel construction with seamless rollers and bushings, and oversized special alloy pins for added strength All components are heat-treated using RK's exclusive HIT (Heat Induction Transfer) process GB520MXZ racing chains are the strongest in their class giving you the best value-performance rating of any MX racing chain in the world today With a maximum tensile strength rated at 9000 foot pounds and weighing in at only 2.89 pounds, the GB520MXZ4 is ideal for professional level 125cc to 500cc open class racing