The Large Bore HD Performance DPF-Back exhaust features 4" 409 stainless steel tubing with smooth curves and increased size to help remove restriction and keeps exhaust gasses flowing smoothly. The OE style band-clamps and bayonnet style hangers make sure this system installs cleanly and easily. ATLAS 5 IN Aluminized Steel DPF-Back Exhaust System w/Black Tip Dodge Diesel Trucks 13-18 L6-6.7L (td) Dodge Diesel Trucks 13-18 L6-6.7L (td)