This is MagnaFlow's Cat-Back for the GMC Sierra or Chevy Silverado 1500. The Off Road Pro Series features a 3" Main Piping Diameter with an Exit Style Turndown In Front Of Rear Tire. 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 3" and a length of 11".