In a word, POWER! That's what our new RS-12 Signature Series full systems delivers for the all new Kawasaki KX250 Motocross machine. Our new RS-12 adds lots of power to the new and improved 249cc Kawasaki powerplant. The goal was to add more usable power and torque to almost the entire power curve. Boasting an increase of max HP of 4.5% (at 12,000 rpm) and a max torque increase of 7.7% (at 6,700 rpm) RS-12 lays the power down to where it needs to be! Of course the RS-12 has more features than just power. Its machined joints, PTF sound inserts, asymmetrical shape are all performance enhancing. With a matte carbon fiber end cap and that Yoshimura bark will make your KX250 the most distinctive on the track! Yoshimura RS-12 and the Kawasaki KX250 are ready for the podium! Kawasaki KX250 RS-12 Features and benefits: Aggressive intelligently designed, the RS-12 asymmetrical shaped muffler allows maximize capacity and incorporates a resonance chamber for managing sound and increasing usable power. RS-12's unique profile also provides more clearance for tire and brake caliper. Tapered muffler body inlet design of RS-12 enables the system to be pushed forward in the new Kawasaki chassis thus helping with weight centralization without sacrificing performance. Improved performance gains with refined linear power delivery. Just like the works systems our Factory Racers use, RS-12 systems utilize precision machined joints. Machined joints provide a superior and exacting fit for joints by better securing the seal between two surfaces with a perfect 360 degree contact surface which translates into improved system life, fit and performance. New patent pending Precision Taper Fit (PTF) insert ring makes it easy to install and remove sound inserts and spark arresters. Works-look matte carbon fiber end cap with industry leading design, innovation and detailing as expected from Yoshimura. Carbon end cap covers the RS-12 inner cap, thus improving looks, while providing easier service as compared to other sandwich mounting designs most commonly found in the industry. Proudly designed, developed and made in the USA! Repack Kits, optional Inserts and Spark Arresters are available for all models