Filter fans provide economical cooling options for electrical/electronic enclosures. The STEGO Filter Fan Plus series uses a new air flap design for the air outlet. The air flaps have less resistance to airflow than an exhaust filter, which allows the Filter Fan Plus system to achieve higher airflow while still preventing the ingress of contaminants. In five fan sizes and airflows up to 243 CFM, two airflow systems are available. The FPI system has an intake fan with filter and an exhaust grille with air flaps; the FPO system uses an exhaust fan with air flaps and an intake grille with filter. A true "no screw" mounting system with four 6-position ratchets firmly mounts the fan. Starting at $60.00, the STEGO filter fan plus series is IP54 dust and splash waterproof rated; 115 and 230VAC plus 12, 24, and 48VDC models are available.