RK's MXZ4 chains are made for supercross and motocross racing. MXZ4 chains feature chromoly steel construction with seamless rollers and bushing. RK's Chromized pins drastically improve the wear resistance more than two times compared to normal non-sealed chains while absorbing shock loads from extreme jumps. All components are heat treated using RK's exclusive HIT (Heat Induction Transfer) process. 520MXZ4 has a maximum tensile strength rated at 8,000 lbs and is suitable for professional level 125cc to 500cc class racing. MXZ4 technology is also available in 420 and 428 mini bike pitch sizes.