Exhaust Silencer: Turbine Core 2: Low maintenance, light weight and power retaining are terms not usually associated with a Spark Arrestor; not until FMF's Turbine Core II. Using the exclusive Turbine Dampening System this top-notch product has well earned its U.S. Forestry Legal status. The straight through design of the spark arrestor canister and the Performance Flow stainless steel end cap ensure strength, durability and most importantly track and trail proven unrestricted power. ,