Airtight galvanized shell housing is perfect for commercial code applications. Powered by ebm-papst external rotor motorized impeller for excellent heat dissipation, even at low RPM. Has a backward curved impeller. Permanently lubricated sealed ball bearings for maintenance-free operation. Automatic reset thermal overload protection. 100% speed controllable. Rated for airstream temperatures up to 140°F. Power cord and strain relief included, but not wired in.