K&N Precleaner Wrap K25-1770The K&N Airforce Pre Cleaner is a specially designed foam filter wrap made to extend the service interval of your K&N air filter when used in very dusty conditions. The Airforce Pre Cleaner is designed to be cleaned with K&N Cleaner or soap & water. Airforce pre cleaners are oiled with K&N air filter oil after they are cleaned. They are made from large, open cell foam. Features: Extends service interval of your filter in very dusty conditions. Large