Performance air filters for Stage 2 Big Sucker Air Cleaners. Stage 2 Air Filters are 20% larger than Stage 1 for increased airflow. Made from the finest materials available, each Big Sucker air filter provides added airflow while filtering out harmful debris on Stage 2 intakes. Each Performance Air Filter is washable / re-useable Red Pre-Oiled Filters are made from 4-layers of surgical grade cotton .