The Grand Rock 4 In Tube Type Exhaust Diverter HDT-4A is a practical and efficient solution for redirecting exhaust gases. With its 4-inch T-shaped tube design, this exhaust diverter fits most makes and models prior to 2007. Featuring a 4-inch O.D on all sides, it ensures optimal performance and durability. Please note that this product is not approved for use on 2007 and later emission engines. Sold individually, this exhaust diverter offers a reliable and effective solution for redirecting exhaust gases in a variety of applications.