Yoshimura Sound Insert Kit Rs-12 Muffler, 1.625" (Ins-31-K)Yoshimura Sound Insert Kit Rs 12 Muffler, 1. 625" (Ins 31 K) Replacement Low Volume Insert Kit for RS 12 Mufflers Non Spark Arrested Available as optional kit on applications requiring different sound restrictions Decibel reduction depends on application This product was designed to fit on a standard equipped motorcycle, as delivered from the factory. OE and aftermarket accessories not found on a bike as delivered from the factory may not be