As we all know, when it comes to Diesel trucks, More Air Plus More Fuel = More Power! But if your air filter gets clogged with dirt and debris, your power will suffer. With the Sinister Diesel Pre-Filter Sock you can add an extra layer of defense to keep your filter clean longer! It filters debris down to 5-microns and has been tested to show no significant drop in airflow. Protect your truck and your investment with a Pre-Filter today!