15-18 HONDA CBR300R: M4 Standard Slip-On Exhaust (Carbon Fiber) M4 Exhaust manufactures exhausts which add power and a more race-inspired sound to your bike as well as lowering the overall weight. Extra time on research and development ensures your exhaust has the ultimate in quality workmanship, ease of installation, and the best performance possible for your motorcycle. M4 Exhausts are available in both Standard / Race and GP Series mounting configurations. The Standard / Race Series Exhaust mounts in the stock position; M4 supplies you with a race bracket to allow the removal of your passenger foot pegs, if desired. Whether hitting the track or sharing a ride with someone, this system has you covered.