EXCEPT ZR2 AT4X models. This extension pipe is used to adapt the BORLA 147.4 Wheelbase Cat - Back systems to fit Crew Cab with Standard Bed (6' 7) 157 Wheelbase vehicles. 3.5 ID inlet, 3.5 OD outlet, 12 long. Includes 1) 3 clamp. Built from premium, high - quality austenitic T - 304 stainless steel, to give you the absolute best in performance and durability. Precision computer numerical control (CNC) manufacturing ensures an accurate fit. Best of all, BORLA stands behind every extension pipe with a Million - Mile Warranty. Just what you'd expect from the world's most experienced (and most winning) exhaust brand.