Yoshimura Spark Arrester Kit Rs-4S Muffler, 1.500" - YO-SA-13-KYoshimura Spark Arrester Kit Rs 4S Muffler, 1. 500" Replacement USFS Approved Spark Arrester for RS 4 Mufflers with "Turn out" end cap. Available as optional Spark Arrester on applications not originally equipped with a Spark Arrester Kit Includes: Spark Arrester Insert End cap collar Set screw 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