Aqueon Deluxe Full Hoods are custom fit to sit on the inside lip of the aquarium frame, which greatly reduces evaporation. A full length door provides roomy access in the front, and cut out sections in the rear allow installation of heaters, power filters and other popular accessories. Includes a full-spectrum fluorescent lamp. Perfectly compliments All-Glass/Aqueon 15, 20H, 25, 30X aquariums and designed to fit all major brands of aquariums (please check measurements). Use 2 for 33L, 40L and 55. Frame, top openings: 23-1/4" x 11-1/2".