RK Chain GB520MXZ4-120 Motocross 120 Link Racing Chain MXZ 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 GB520MXZ4 being a light and strong Motocross chain, it is ideal for professional level 125cc to 500cc Open Class racing Tensile strength is 9000 pounds per feet All components are heat-treated using RK's exclusive HIT (Heat Induction Transfer) process