Yamaha YZF600R Thundercat 14&rdquo; Stainless Oval Muffler Exhaust 95-03 04 05 06 07 YZF600R THUNDERCAT(1995-2007) Delkevic Stubby 14" Mufflers are made from high grade 304 stainless steel polished to a mirror finish. All parts are hand welded with superior look and sound to the stock exhaust. The weight of the muffler is 4.28 lbs. 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.