Improves airflow up to 92 Percent. Nearly doubles flow. 4-inch constant-diameter downpipe-back system with Straight-through muffler. Easy install. Tip optional. Compatible with factory warranty. Monster Performance and Modest Price. Banks' new Monster Sport Exhaust is one cool 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 exhaust system. Virtually eliminates backpressure and nearly doubles the flow! Lowers exhaust gas temps. Straight-through Monster Muffler delivers a commanding exhaust note. 100 percent Stainless Steel. Easy install. 5 inch rolled-edge polished tip is optional. Fully compatible with the Ford factory warranty. 5-Year Limited Warranty. Key Features: Mandrel bent Stainless Steel construction Virtually eliminates backpressure Lowers exhaust gas temps Dramatically improves flow Maximum Airflow Improves airflow up to 92 percent Nearly doubles flow 4 inch constant-diameter cat-back system Straight-through muffler Easy install Tip optional Compatible with factory warranty 5-Yr Ltd Warranty CARB E.O. Not Required