Fully-assembled outboard and inboard joints installed on a 4340 chromoly-steel axle bar. 8 Ball Extreme Duty Axles feature all internal precision-ground components that are assembled using high-temperature, high load-bearing moly grease. Eight (8) precision ball bearings allow for smoother operation and increased join strength. Up to 35% larger cages and races - increasing strength and durability. Black oxide coating for ultimate rust and corrosion protection. Precision machined for precise O.E.M. fitment. Assembled using stainless steel low-profile clamps. Includes a spindle nut and washer, where applicable. All facilities are registered ISO/TS16949 - ISO 9001. One-year manufacturer's warranty. Engineered in U.S.A.