420MXZ chains are made for the serious Motocross racer looking for the lightest, strongest Non O-ring Chain. 420MXZ chains feature Chromoly 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. 420MXZ 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 5000 foot pounds and weighing in at only 1.76 lbs., the GB420MXZ is ideal for professional level 50cc to 125cc Open Class racing