Air King 9166F 20" Whole House Window Fan 3-speed, 1/6 HP, 120V, 1 phase, permanently lubricated Front mounted rotary switch and RPM (High/Med/Low) is 1600 / 1450 / 1100 Front Mounted Switch, Impact Resistant Plastic Housing, Powder Coated Steel Front Grill and Blade OSHA approved. dB - (High/Med/Low) 	64 / 57 / 50 Fits window openings that are between 27" to 38 wide by 26.25" high.