The Grand Rock Tube Type Exhaust Diverter HDT-49090A is a 4-inch tube type exhaust diverter that fits most makes and models prior to 2007. It is ideal for Mack Granite and features a 4 In I.D/4 In O.D. However, the parts are not approved for use on 2007 and later emission engines. Sold each, this exhaust diverter is practical and beneficial for those looking to upgrade their vehicle's exhaust system.