This is similar to our Level 5 axle except the outer CV is made from Billet Chromoly and the internals are also made from the same high-grade material. We use the original spline size to fit the stock hubs. To make sure the center bar was up to the task of hard launches, autocross, and rally demands, we have decided to use the new 300M material. This material has proven to be, without a doubt, the strongest and most resilient bar material we have to date. Recently we have changed the inner CV from a tripod design to a full ball and cage design with a larger radius to the spline plug for added strength. So there you have it, a direct-fit axle that will withstand the most violent launches, time attacks, or rally applications. (Ask about the road rally package that uses ultra-high-grade grease and vented boots)
Please Note: These axles are for the 2009-2015+ STi models ONLY