Yoshimura Sound Insert Kit 2M-Max Rs-4 Muffler, 1.375" (Ins-2M26-K)Yoshimura Sound Insert Kit 2M Max Rs 4 Muffler, 1. 375" (Ins 2M26 K) 2 METER MAX Replacement Low Volume Insert Kit for RS 4 Mufflers Non Spark Arrested Available as optional kit on applications requiring different sound restrictions Decibel reduction depends on application Kit Includes: Low Volume Insert Tube End cap collar Set screw This product was designed to fit on a standard equipped motorcycle, as delivered from the factory. OE and aftermarket