USFS Approved Spark Arrestor End Cap. The stock silencer looks and works great, is very quiet and very light, so instead of replacing the whole silencer we can offer you a more cost effective option. Our end cap was designed using the latest CAD design software. It was designed to offer maximum performance; in our testing we found no power loss from the stock end cap. The EE screen type spark arrestor makes maintenance very easy, by simply removing 2 bolts the screen can be removed for replacement or servicing. The easy access to the screen is great for riders that use their bikes for Closed Course and O?-Road, no need to have two silencers.. SPARK ARRESTOR END CAP