Allegro 9504 centrifugal blower is excellent for most ventilating needs, especially confined space. Allegro 9504 blower is designed with a tough polyethylene housing, metal safeguards and a steel fan for durability. Allegro 9504 centrifugal blower has two 8" ports offering positive ventilation or fume extraction, and the metal base with feet offers greater stability. The 9504's electric motor is cage-enclosed for protection. Comes with an on/off switch and built-in carry handle for increased portability. Works great with generators. Air delivery certified CEESI.