Self contained 11-1/2 quart insulated pail. Maintains constant water temperature and proper aeration. Runs 100 hours on a pair of D cell alkaline batteries. Waterproof. 1/2 styrofoam shell removes for quick cleaning. Insulated hinged door. light to carry and tough enough to sit on. 3.5 gallon container 10.5 quarts/9.9 Liters Pumps 1.0 STL/minute Runs up to 85 hours with two alkaline D batteries, but can also run off of one battery .75 inch insulating foam liner