The 2.5" piping and cast intake horn on the first gen Cummins is a known choke point. This pipping kit is made from 3 inch stainless steel and helps smooth the air flow as it enters the intake manifold. Paired with the PQY intake heater block delete this kit removes all the restriction for the charge air. It not only makes performance gains but looks much better too. Kit comes with everything you will need to install it. -3 inch Stainless steel intake horn, Cold side pipe and hot side pipe. -(4) M8×1.25×75 bolts. -New gasket for intake horn. -(3) 3 inch to 2.5 inch silicone coupler. -3 inch silicone coupler. -(8) T-bolt clamps