Features: high temperature performance, high efficiency, easy installation, reliable operation (to produce a single-speed, two-speed, variable frequency stepless, roof exhaust fan fire and explosion Fire-type special fan) and get the fire product license. Purpose: tall buildings, ovens, tunnel boxes, underground garage and specialty industrial and mining enterprises and other fire temperature exhaust, exhaust. Specifications: Fan diameter: Φ350 ~ 1500mm Airflow: 3350 ~ 93800 m3 / h Pressure 280 ~ 819Pa.