These fans are designed for exhausting general clean air where height and looks are a concern. The housing is a low silhouette style with interlocking rib construction, providing superior strength. Formed channels adjacent to the ribs provide water drainage to ensure weather tightness. Hoods have hinged galvanized steel supports for service access. Capacities range from 100 to 37,500 cfm and up to 2.0 in. wg.