The 3" diameter into dual 2.25" Borla(r) Cat-Back(tm) system was specifically designed to enhance the power and sound of the Ford F-150 equipped with 3.3L engine. The split rear exit configuration replaces the single factory tail pipe, and has single 4" round black chrome on T-304 stainless steel tips on each tail pipe. 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. A system with bright chrome on T-304 stainless steel tips is also available. This system features the aggressive ATAK(r) sound with no drone. Additional systems are available with different options for sound level, tip finish and tip exits. Add adapter 60556 for Crew Cab with Standard Bed (6' 7") 157.2" Wheelbase vehicles. Add adapter 60564 for Extended Cab with Long Bed (8' 2") 164.1" Wheelbase vehicles. Borla(r) Cat-Back(tm) & Axle-Back exhaust systems feature patented straight-through and multi-core technology 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 stainless steel, to give you the absolute best in performance and durability. Ultra-smooth mandrel bends ensure maximum flow & power, and computer numerical control (CNC) manufacturing ensures an accurate fit. All this is backed by our unsurpassed Million Mile Warranty. System Features: Cat-Back(tm) System Split Rear Exit 4" Round Black Chrome On T-304 Stainless Steel Tips ATAK(r) Sound Level T-304 Stainless Steel Construction Bolt-On Installation Million Mile Warranty