Stainless Straight Pipe kit for 4 inch Banks Power Monster Exhaust Systems. Does not replace OEM muffler. Replaces Muffler 53800 used in 2001-2007 6.6L Duramax and 1998-2007 5.9L Cummins 4 Inch Monster Exhausts. Includes 4-inch x 28.5-inch Exhaust Straight Pipe and all necessary hardware.