This is MagnaFlow's Cat-Back for the GMC Sierra or Chevy Silverado 1500. The Street Series features a 4" Main Piping Diameter with an Exit Style Single Passenger Side Rear. The Inlet Connection Type is a basic Clamp-On with a Straight-Through Muffler Type made of Stainless Steel with a Satin finish. The Tip Shape is Round with a Diameter of 4" and a length of 13".