15-19 POLARIS RANRZR900S: Polaris Genuine Accessories High Performance Air Filter The Polaris high performance air filter was co-developed by Polaris and Donaldson to create the highest performing air filter for this vehicle. It uses Donaldson exclusive Ultra-Web&#174; Nanofiber Filtration Technology which offers a higher initial efficiency compared to standard cellulose media and has very high efficiency throughout a filter&#39;s life.Best engine protection - 99.99% efficient