Top qualitty German made motor with galvanized steel housing and baked on powder coat finish. Powered by external rotor motorized impeller for excellent heat dissipation. Automatic reset thermal overload protection. Permanently sealed ball bearings. External wiring box for ease of connec- tion. Tested and approved by UL and CSA, FX Series fans are suitable for air stream tempera- tures up to 140° F. 100% speed controllable.