Where the clear-lid version of Ronco's 4 inch inspection port is about seeing in, this all-white version is about everything staying out: an opaque white lid on a white collar that closes the port completely and keeps light out of the stored water. On a white or natural tank the whole assembly nearly vanishes - a service port that does not announce itself.
The 4 inch opening is the small-format port: sized for visual checks when opened, sampling, and wand access rather than hand-and-arm cleaning. If your maintenance plan is to open the lid on a schedule rather than glance through it daily, the solid lid gives up nothing.
Like all of Ronco's installed hardware, the collar goes onto your tank at the Tustin, California plant at order time - a practice as old as the company's 1974 founding - so tank and port arrive as one finished piece. Pair it with anything from the RV water tanks or RV holding tanks ranges, or browse the Ronco Plastics hub for the full line.
OneSource Plastics is an authorized Ronco Plastics dealer.