Banks Power Extension Kits are made from durable galvanized T-409 Stainless Steel. These kits come with necessary hardware for the applications listed in their description. Exhaust Extension Kit, Stainless Steel, for use with GM 8.1L P-Series Motorhome, 208 inch W/B Wheelbase. Key Features Extension kit, stainless Includes 4-inch Extension Pipe and all necessary hardware