BORLAs XR-1 mufflers actually outflow a straight piece of pipe in repeated testing. XR-1 race products are light weight and constructed of high quality austenitic stainless steel for track-tough durability. They meet the strictest noise requirements and use sound absorbing stainless steel packing to protect against burnout. Hands down, BORLAs XR-1 Raceline offers the best balance of sound and power. Description:XR-1® Stainless Multicore Racing MufflersBody Height (in.):5.5Body Length (in.):34Body Width (in.):8.5Inlet Position:CenterInlet Size (in.):3Inlet Type:Single Center InletMaterial:Stainless SteelOutlet Position:CenterOutlet Size (in.):3Outlet Type:Single Center OutletOverall Length (in.):39Shape:OvalInlet Connection Type:PipeMaterial:304 Stainless SteelBody Height:5.500 in.Body Length:34.000 in.Body Width:8.500 in.Inlet Outside Diameter:3.000 in.Inlet Type:Single CenterMain Piping Diameter:3.000 in.Outlet Outside Diameter:3.000 in.Overall Length:39.000 in.