The Pro Circuit Ti-4 GP system is designed as a total performance exhaust system. The Ti-4 GP Low Boy version was designed to lower and centralize the dirt bikes center of gravity for better handling. This exhaust system is dyno and track tested by riders like James Stewart, Ricky Carmichael and Ryan Villopoto as a no-compromise full-race exhaust. The ultra-lightweight titanium Ti-4 GP is Pro Circuits premium exhaust system and it includes their titanium header pipe. The Ti-4 GP exhaust will boost performance from bottom all the way to the top end, making it easier to ride and lowering lap times. The silencer can is easily repacked simply by removing the inlet cap screws and re-wrapping the silencer core. The Ti-4 GP meets all AMA sound restrictions. This is the exact same exhaust system that won four out of five AMA National and Supercross titles in 2007. Designed as a "full race" exhaust system. Includes a U.S.F.S.-approved spark arrestor which can easily be replaced with the race tip (included) for closed-course competition. Bottom to top end power increase. Meets AMA / FIM sound requirements of 94db. CNC machined billet aluminum mounting bracket on canister for increased durability. CNC machined exhaust flange on head pipe for perfect fit. Three-piece system that includes canister, mid pipe and head pipe. Ultra-strong mounting bracket on mid pipe for extended product life.