The Aluminized Custom Builder Pipe Kit Series has a limited 1 year warranty and offers the most options for customization. For the Racer, it provides a mandrel bent pipe-only exhaust from Turbo to tailpipe complete with all hardware. For the street driver, the CBPK is the basis for a custom exhaust that allows you to purchase and install the converter, muffler and tip of your choice. Custom Builder Pipe Kit Diesel Performance Exhaust System; 4 in. Down-Pipe Back; Incl. Tubing/Tailpipes/Hardware; No Tip Incl.; Single Pass. Side Rear Exit; Aluminized; The Custom Builder Pipe Kit features Aluminized construction and offers the most options for customization. Complete your system with the required converter; muffler and tip for your application.