The uniform thickness of the tanks makes them much more durable than the traditional rotational molded and thermoformed varieties Alpha Systems blow-molded HDPE tanks are an integral component to all recreational vehicles Alpha Systems backs all of the tanks with a 12-month warranty from the date of purchase; Alpha tanks are built to standards specified by IAPMO (International Association of Plumbing and Mechanical Officials) and the Canadian Standards Association 22 Width x 54 Length x 8 Height Holding Tank 33 - Gallon, Blow-molded with 3 Inch Coupling The uniform thickness of the tanks makes them much more durable than the traditional rotational molded and thermoformed varieties Alpha Systems blow-molded HDPE tanks are an integral component to all recreational vehicles These RV holding tanks (waste water) have standard configurations with the option to customize fittings Alpha Systems backs all of the tanks with a 12-month warranty from the date of purchase; Alpha tanks are built to standards specified by IAPMO (International Association of Plumbing and Mechanical Officials) and the Canadian Standards Association 22 Width x 54 Length x 8 Height Holding Tank 41- Gallon, Blow-molded with 3 Inch Coupling