Honda CBR250R DS70 9&rdquo; Carbon Fiber Oval Muffler Exhaust Slip On 11 12 13 14 2011-2014 Delkevic DS70 9" oval carbon fiber mufflers are made from a pre-formed composite carbon fiber sleeve and 304 stainless steel. They have a large 2 3/4" outlet amplifying the sound. They are short, crips and LOUD. This set includes all necessary hardware to mount the muffler onto a stock header. If gaskets are required for installation, they are provided. No rejetting or remapping is required after fitment on a stock bike however we always recommend a dyno test. If the motorcycle has other modificaitons to the intake or exhaust system some tuning may be required. Delkevic mufflers are handcrafted from the finest quality materials to enhance your motorcycle in both performance and looks.