These incandescent hoods can be used on most brands of aquariums. They fit on the lip of the aquarium frame for a nice finished look. The Economy hoods feature a one piece design with lexan bulb splash shields for longer bulb life. 16 and 20 Deluxe Incandescent Full Hoods feature full length door and convenient rear cut-out sections for popular accessories. All hoods are the latest design and are U.L. listed. Bulbs are not included. Dimensions: 20.