Twisted and aggressive, just like how you like to ride. Features a double-stepped header system, providing stronger scavenging effect and better performance, as well as higher horsepower and torque gains over stock. The unique over/under design gives aggressive sound and performance. Each Cross Back system is designed with 18mm O2 sensor ports for closed-loop fuel and dyno tuning. Customize in your choice of chrome or black with chrome or black end caps. Exclusive Rinehart Racing logo on 2.5? full-coverage heat shields.