At 40 x 20 x 10 inches the B424 is a genuine under-bunk tank: 30 gallons spread low and flat so the mattress platform above it barely notices. Ten inches of height is the dimension that matters here - it slides beneath berth flats and settee bases that a taller square tank cannot enter, and the low profile keeps the filled weight close to the hull where you want it.
Marine or RV, fresh or waste, the shell is the same dual-role B-series molding. Order potable fittings and it is a water tank; order sanitation fittings and it is a gray/black holding tank. Either way Ronco installs them to your marks - spin-welded or threaded - before it ships. Print the drawing below, mark the fitting positions your plumbing needs, and let the on-page fitting planner sort the sizes.
The blank weighs 84 lb; full, the 30 gallons adds about 250 lb, so the berth flat under it should be solid ply, not slats. Rotomolded in Tustin, California, as Ronco has done since 1974. See other low-profile shapes in the boat tank range and the RV water tank range. OneSource Plastics is an authorized Ronco Plastics dealer.
Technical drawing: download the Ronco Plastics B424 dimensional drawing - print it to plan your install and mark exactly where you want fittings located; Ronco installs spin-weld or threaded fittings to your marked spec.
