Improves airflow up to 176 Percent. 4 - inch constant - diameter cat - back system nearly triples flow. Straight - through muffler. 5 - inch tip optional. Fully compatible with factory warranty. Monster Performance Modest Price. Banks' new Monster Sport Exhaust is one cool cat - back system And its low price That's way cool. The system slashes backpressure, increases exhaust flow, improves fuel economy and delivers extra power to your rear wheels. Exhaust tip optional. 4 inch constant - diameter cat - back exhaust system. Virtually eliminates backpressure nearly triples flow Lowers exhaust gas temps. Straight - through Monster Muffler delivers a commanding exhaust note. Stainless Steel. Easy install. 5 inch rolled - edge polished tip is optional. Fully compatible with the ChevyGMC factory warranty. 5 - Year Limited Warranty.