Ronco molds 26 gallons three different ways, and the B338 is the middle path: 39 lb of polyethylene, heavier-walled than the light blank, without the full armor of the heavy-service shell. That middle weight is the right answer more often than either extreme - enough section to shrug off slosh and vibration for decades, still light enough that one person can maneuver it through a cockpit locker and into position without help.
Like its siblings it ships without fittings, because Ronco's whole marine program is built around your drawing, not theirs. Print the plan below, mark every port with the on-page fitting planner - fill, vent, pickup, sender - and each fitting is spin-welded or thread-installed to those marks in Tustin, California before shipment. That has been the process since 1974. For potable service the molding is FDA-compliant; and as with every dual-role B-series shell, ordering waste fittings instead turns the identical blank into a gray or black holding tank.
Full, it carries about 217 lb of water. Support the bottom, strap the top, and it will outlast the upholstery. If you want to compare all three 26-gallon walls side by side - or jump a size in either direction - the boat tank category lays out the options, and the Ronco Plastics hub holds the maker's entire line. OneSource Plastics is an authorized Ronco Plastics dealer.
Technical drawing: download the Ronco Plastics B338 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.
