The 3W is one of the oldest shapes in the Ronco book, and the reason is visible in the numbers: 12 gallons at 29.75 x 13.88 x 8.12 inches. That is a tank sized to the voids vehicles actually contain - under a bench seat, over a wheel arch shelf, beneath a bunk in a small cruiser. Not so big it forces a redesign, not so small it feels like a gesture.
It is molded in the Water / Waste Holding Tank series, which means the RV-or-marine, fresh-or-waste question is answered by your fitting order, not by the part. With potable fittings it is a fresh tank in FDA-compliant polyethylene. With drain fittings it is a 12 gallon gray or black holding tank. Same shell, opposite plumbing.
At 9 lb empty it is a one-person install; full it holds about 100 lb of water at 8.34 lb per gallon. The RV water tanks category surrounds this size with flatter and deeper options, RV holding tanks handles the waste side, and the same low profiles appear across the boat tanks range.
Made in Tustin, California, where Ronco has rotomolded continuously since 1974. Fittings are installed per order - spin-weld or threaded, wherever you mark them: print the drawing below or use the click-to-place fitting planner. OneSource Plastics is an authorized Ronco Plastics dealer.
Technical drawing: download the Ronco Plastics 3W 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.
