Pro Moto Billet PMB-01-5104 Blue Endos Spark Arrestor End Cap Fits: Yamaha YZ450F 2008-2009, Blue anodized removable end cap nozzle Pro Moto Billet designed their spark arrestors as an economical way to convert your stock muffler into a U.S.F.S. approved spark arrested muffler When the spark arrestor screens are not required such as at the MX track simply remove three machine screws on each end cap and take out the screens, it's as simple as that Each end cap is machined out of solid 6061 aluminum and anodized with a protective finish Each spark arrestor includes an end cap assembly with, removable nozzle, a spark arrestor screen, and all required mounting hardware