While other exhaust brands just carried over their Yamaha YZ250F offerings to include 2024 model, on the dyno & track, the new YZ told us there was more on the table. So our R&D team went to work to optimize the new Yamaha. Revised for the 2024 is our RS-4 slip-on for the new YZ250F. Adding 1% max HP & 1.2% max torque, the RS-4 slip on is a great option for adding some power. RS-4 also has the ability to add a spark arrestor for off-road adventures. Yoshimura's RS-4 system is proudly designed, developed & manufactured in Chino, California. * Pentagonal-shaped sleeve * Front muffler cap functions as a polyresonant chamber which helps reduce noise * Two-stage stepped baffle * Carbon fiber end-cap * Stainless steel tail-pipe Article: YOSHIMURA YOSHIMURA RS-4 Signature Series Silencer