The BBR Tuning High Performance F2 Thrust Muffler (Black) is perfect for giving you more power and sound out of your 2-stroke motor. Made for racing and performance engines, you can forget that old muffler you're using and replace it with the Thrust muffler for better power and speed. Instead of using a baffle that will hinder your performance, the BBR Tuning F2 Thurst muffler makes use of its baffle-less design to expel more from your motor. This utilizes expansion chamber technology to circulate the air around the chamber and out of the muffler for a smoother ride. Its length will also let you expel air faster and more efficiently, just like a stretched or long-shot muffler would. Note: This muffler will raise slightly upward and over the magneto/drive sprocket side cases, going to the back of your bicycle. Though it will hug the engine tight, please use caution when riding as to not rest your leg against the muffler after each ride.