The RVB300 is the largest fresh water molding in this run of Ronco's light-duty book - the maker's B-300 L.D., a one-hundred-and-thirty-five gallon tank. Capacity like this is for the coaches that treat water as range: mobile crews, desert winters, families who measure trips in weeks. It is more water than most RVs can structurally carry, which is precisely why the rigs built for it are built around it.
It is molded in translucent natural polyethylene, FDA approved for potable service. At this volume the see-through wall stops being a nicety - it is your fuel gauge for the resource that decides when you go home. The blank ships with fittings installed per order: Ronco spin-welds or thread-installs them at the locations you mark, so the ports match your manifold rather than forcing the manifold to match the tank. Print the drawing below, plan against the real bay and real plumbing, and enter the layout in the fitting planner on this page.
Ship weight is 142 lb; the water will weigh far more, so treat the floor of the bay as structure, spread the load across the tank's full base, and check axle weights after the first fill. Molded in Tustin, California by a shop that has done nothing but this since 1974.
If the bay will not take it, step down through the big end of our RV water tank category - the RV66W is the nearest sibling below. The full line is on the Ronco Plastics hub, and freight at this size should be quoted up front in the freight estimator. OneSource Plastics is an authorized Ronco Plastics dealer.