Weatherhood, For Blade Diameter 16 in, For -Out Height 18 1/2 in, For -Out Width 18 1/2 in, For -Out Height (With Wall Collar) 21 5/8 in, For -Out Width (With Wall Collar) 21 5/8 in, Overall Height 20 1/4 in, Overall Width 20 1/4 in, Overall Depth 17 in, Material Steel, Thickness 20 ga, Finish Galvanized