The Pro Circuit spark arrestor is a very lightweight silencer that meets U.S.F.S. Fire Safety as well as noise standards for 2-stroke motorcycles. Pro Circuit developed their Spark Arrestor Silencer using both experience from their racing background and the Krizzman bullet clog-free design; it eliminates the chance of spark leaving the exhaust system and muffles sound without hindering performance. The Pro Circuit Spark Arrestor is designed for 2-stroke motorcycles to allow them to perform with outstanding results while also allowing riders to use forest trails or any tracks that require spark arrestors. Meets U.S. Forest Service standards without sacrificing performance or horsepower. Specially engineered internal metal baffle eliminates the chance of a spark leaving the exhaust system. Clog-free Krizzman bullet design. FIM-approved 304 stainless steel end cap. Stainless steel intake tube.