The Stainless Steel Sunvent provides continuous ventilation whenever there is sunshine. No batteries, wiring, plugs, or noise. Clear cover protects solar panel, and is designed to keep water and back drafts out. May even be used on the deck of a boat! Sunvent extracts 680 cu. ft. of air per hour. Very easy to mount requires 4 3/4" dia. installation hole. 8 1/2" dia. Great for: RVs - attics- Dog Houses - Port-A-Potties - Hot Tub Rooms - Lofts - Stables - Greenhouses - Boats - Solar Porches - Farm Buildings.