XFORCE - 4" Inch Inlet & 4" Inch Outlet Oval Varex Muffler is a high-quality product that features a 4" inch inlet and 4" inch outlet, with a single wall outlet style and a diameter of 61/2 x 10 inches. The inlet length is 3 inches and the outlet length is 5.5 inches, giving you optimal performance and sound control. This muffler is part of the Varex product group and is recommended by industry experts for its superior performance.