Corrosion resistant fiberglass housing has smooth shape with gel coat inside for easy maintenance and maximum airflow. Single-phase totally enclosed motor has sealed ball bearings and automatic thermal overload protection. Slant wall housing provides efficient airflow. Features include poly shutters, variable speed and 3 poly fan blades. Models 968694 & 968695 have 1-speed and a poly cone that enhances fan performance. 36" Diameter Model has 3 stainless steel blades. 50" Diameter Model has 3 cast aluminum blades. 115V/230V. UL listed. 2 Year Limited Warranty.