The number that makes the RVB401 interesting is not the 70 gallons - it is the 52 pounds. Most B-series tanks in this capacity class weigh twice as much; this molding puts a genuinely useful fresh water supply into a package one person can maneuver into an under-bunk cavity or a tight basement bay without help. For van conversions and self-builds where every pound of dry weight competes with gear, that ratio is the whole argument.
It is a light-duty Ronco molding in translucent natural polyethylene, FDA compliant for potable water, from the same Tustin, California plant that has been turning out B-series tanks since 1974. The translucent wall reads water level directly - useful in a tank that often ends up buried under a bed platform where a mechanical gauge would be awkward to route.
Plan the full-weight case even though the tank itself is light: water runs 8.34 pounds per gallon, so the loaded tank is a real load that belongs over structure. Ronco installs all fittings per order - spin-welded or threaded, at your marked locations - so print the technical drawing below, mark your fill, vent, and supply points, and confirm the layout in the fitting planner on this page before ordering.
More footprints live in the RV water tank category, and the complete molding list is on the Ronco Plastics hub. OneSource Plastics is an authorized Ronco Plastics dealer.