Hooker Cat-Back Exhaust Systems use large 3" diameter 16 gauge mandrel bent aluminized intermediate pipe for maximum power efficiency and longer life. These popular cat-back systems feature Hooker Aero Chamber mufflers, which produce more horsepower and torque than other popular chambered mufflers and they have a throaty powerful sound that will not change with time. F-body systems have two tailpipes (one on each side), each ending with a dual 3" Exhaust tip.