The FMF Gnarly pipe focuses on increasing the lower RPM horsepower and torque to get you out of the toughest terrain. When looking to add 4-stroke tractor like torque to your 2-stroke and you need a pipe to withstand the harsh elements, this is the pipe for you. Strong and rugged, this aggressive pipe dishes out handfuls of torque and bottom to mid range pull needed for late model 200cc through 500cc machines and the rigors of the off road domain. -Nickel plating is an FMF trademark and has been copied by everyone making it the most imitated expansion chamber in the world. -Super strong18 gauge steel construction makes it GNARLY! -O-Rings Included Make Model Year HONDA CR500R 89-01 Fits: Honda CR500R 1989-2001