This is the Level 5 Rear Axle/Hub system for the Evolution 4/5/6. These axles feature our heavy duty 32 spline center bars, up from the factory 30 spline, that are made from high grade aircraft quality material and are significantly more torsional than the factory bars, billet ball and cage inner CV's with an aerospace grade chromoly spline into the differential, an outer CV that is about 30% larger than stock with larger internals and we also include new hubs to accomodate the larger spline and ARP studs. ABS Rings are not included but can be added for an additional charge. Rated to 800HP with a 1-year warranty.