The PRO DPF Series has lifetime backed stainless steel construction, a muffler-less design and mirror polished welded intercooled tips. The best value system with a no hassle emissions legal design. Aluminized Custom Builder Turbo-Back Exhaust System ; 4 in.; Tail Pipe/Hardware; Single Passenger Side Rear Exit; 4 in. Downpipe; 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.