This is the 600HP Level 2.9 system for the S13 and S14 platform. The Level 2.9 axles feature an outer CV that is a ball & cage type, a great improvement over the 240SX factory tripod style CV, our high-grade aircraft quality torsional center bars that twist more than a factory unit absorbing a great deal of the shock factor and a Porsche style 108mm CV with precision billet adapter plates and hardware to mount to the factory differential stubs. Price listed is for both axles.