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 16 and 20 Hoods feature a one piece design with Lexan Blub splash shields for longer Blub life * 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 16 and 20 Hoods feature a one piece design with lexan Blub splash shields for longer Blub life.