Autanic Car Chrome Exhaust Muffler Tip for Jeep Grand Cherokee 3.5" MATERIAL: good-quality stainless (304); DIMENSIONS: external diameter 3.5", length 4.8"; FITMENT: Jeep Grand Cherokee 2001, 2003, 2004, 2006, 2011; INSTALLATION: installed by screws, easy to install; FUNCTION: to prevent exhaust pipe's distorting and to reduce the noise;