HMF Performance Exhaust Kit for King Quad 450/500. HMF Performance slip-on exhaust, HMF Optimizer fuel injection controller and high-flow Uni air filter and cage. Ready to bolt on and go! Noticeable improvement across the rpm range. Also includes quiet core/db killer to keep your friends riding behind you from going deaf, but easy to take out if you want max sound and performance. $275 OBO.