Acoustic technology applied to exhaust flow delivers high response while lowering sound Larger squared internal area creates more flow Spark Arrestor is incorporated, exhaust flow is split to reduce decibel levels This product can be used with KTM 450EX 2004 KTM 450MX 2004 KTM 450SX Moto 2004 KTM 525EX 2004 KTM 525MX 2004 KTM 525SX Moto 2004