Factory Single Side Exit vehicles ONLY. Add Adapter 60708 for Crew Cab with Standard Bed (6' 7") 157" Wheelbase vehicles. The 3" diameter Borla(r) Cat-Back(tm) system is a side exit system featuring the mellow Touring sound level with no drone inside the vehicle and a 4" round black chrome on T-304 stainless steel tip. A system with a bright chrome on T-304 stainless steel tip is also available. Using Borla(r) Stainless Steel Polish p# 21461 is NOT recommended with these black chrome tips. We suggest cleaning the tips with hot water and a microfiber cloth. Add Adapter 60706 For Crew Cab with Standard Bed (6' 7") 157" Wheelbase vehicles. Borla(r) Cat-Back(tm) and Axle-Back exhaust systems feature patented straight-through and multi-core technology designed to unleash hidden horsepower. Increased exhaust velocity adds power driving excitement fuel economy and the distinctive Borla(r) Sound of Power respected by motoring enthusiasts everywhere. Each system is built from premium high-quality T-304 austenitic stainless steel superior to T-400 to give you the absolute best in performance and durability. Ultra-smooth mandrel bends ensure maximum flow & power and precision CNC manufacturing ensures an accurate fit. Give your Silverado or Sierra the power and sound it deserves bolt on a Borla(r). You can count on Borla(r) to provide durability performance sound and a Million-Mile Warranty. See separate note about warranty on tip finish.