aFe Power 28-10113 MagnumSHIELD Pre-Filter (Yellow) 2x-90015/23 2x-91007/8/22 (Black) aFe Magnum Shield Pre-Filters protect your performance air filter and extends your filter cleaning intervals by removing large particles from the air stream prior to the air filter This pre-filter does not restrict air flow and is made of a dry weave fabric that does not attract dirt and cleans with soap and water.