Outerwears brand pre-filter for your R/C pullstart. A must-have for operating in dirty or dusty conditons! Protects engine pullstart against harmful elements. High air flow for cooling. Washable & reusable - save money by extending service intervals. Water repellent. Includes prefilter, velcro mounting strap, and instructions. Fits most Zenoah and Chung Yang pullstarts. Fits Zenoah G230RC / G260RC engines. Also fits Chung Yang CY23RC / CY26RC / CY27RC / CY29RC / GP290 engines. Fits most large-scale R/C cars, buggies, and trucks - FG, HPI Baja 5b, etc. Will not fit Smartech manufactured 23 & 28cc engines.