Outerwears K&N Pre-Filter Ru-1770 Developed specifically to upgrade the protection your K&N enhanced filter element already offers. Constructed from silicone-impregnated micro-mesh for water resistance and featuring seam welding utilizing dielectric techniques, these pre-filters excel at capturing particles as tiny as .005 in diameter while maintaining optimal airflow to your engine. The material boasts consistent micron-sized apertures that facilitate air passage while effectively screening out undesired contaminants like sand, dirt, clay, and moisture. Features: Dyno and flow bench testing reveals no loss of horsepower or airflow when using this product Keeps your engine safer in harsh conditions Filters particles down to .005 See fitment notes for more filter compatibility