Yamaha YZF-R1 13" Stainless Tri-Oval Muffler Exhaust Slip On 09 10 11 12 13 14 YZF-R1 (2009-2014) Delkevic 13" Tri-Oval muffler is manufactured with high grade 304 stainless steel and polished to a mirror finish. This set includes all necessary hardware to mount the muffler onto the engine. Gaskets are included. 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.