What the maker puts in writing
- “Toilet flapper with solid frame and kink-free chain replaces leaky, corroded flappers, preventing twisting, ghost flushing, and running toilet problems”
- “Adjustable flapper fits most 3-inch flush valve toilets, best for use in high efficiency 1.28 to 1.6 gallons per flush toilets, includes adjustable length kink-free chain”
- “Dial flapper adjusts for maximum flush efficiency and to save water”
- “Durable silicone seal lasts 10X longer than regular flappers and resists chlorine and hard water”
- “This product has a 10-year warranty; Note: this item is not designed to fit 2 inch flush valve toilets”
Ten years, on a flapper
That is the longest warranty on this shelf, and it is on the cheapest kind of part in a toilet.
What makes it credible is the material. A flapper fails because the tank water is chlorinated — increasingly with chloramine — and the rubber hardens, curls and stops sealing. Silicone resists that far better, and Fluidmaster claims ten times the life.
Korky on this shelf answers with chlorine-resistant rubber and publishes no warranty. Danco publishes a silicone seal and no warranty.
Fluidmaster is the only maker here that warrants everything it sells on this shelf: ten years on this, five on its other two.
And hard water as well
Resists chlorine and hard water.
That second clause is unique on this shelf. Chlorine attacks the rubber; hard water does something different — it deposits scale on the seat and on the seal face, so the flapper sits on a gritty ridge and no longer closes flat.
Nothing else on this shelf mentions it.
Ghost flushing, which is the symptom to recognize
The toilet refilling itself for fifteen seconds at three in the morning, with nobody near it.
What is happening: the flapper leaks slowly, the tank level falls, the fill valve notices and tops it up — repeatedly, all night. It is the audible version of the slow leak that drains the most water in a house.
And the flapper is nearly always why. Three possible causes, and this listing addresses all three:
A hardened seal — silicone.
A twisted frame, so it sits crooked — a solid frame.
A chain long enough to catch underneath and hold it ajar — a kink-free adjustable chain.
The dial
It sets how long the flapper stays open, which is how much of the tank leaves.
This is the thing people do not expect: a generic replacement flapper is often the wrong strength for the toilet. Too light and it shuts early, the flush is weak, and you flush twice — which uses more water than the old leaking one did. Too heavy and it dumps more than the toilet needs.
A dial lets you set it after fitting. Fluidmaster publishes one on both its flappers here; Korky and Kohler publish no adjustment at all.
Three inches, said twice
Fits most 3-inch flush valve toilets. And in the warranty bullet: not designed to fit 2 inch flush valve toilets.
Lift the tank lid and measure the opening the flapper covers before ordering. For a 2 in valve the Fluidmaster 555CRP8 kit on this shelf is the right part — and it is a closeout that cannot be returned.
What Korky has that this does not
A published stainless steel chain. Fluidmaster publishes that its chain is kink-free and adjustable, and not what it is made of — and a rusted chain in two pieces is the other way a flapper stops working.
Four dollars ninety-one separates the two. This has the warranty and the dial; Korky has the chain.
Availability
Available at around $16.89 on Amazon.com when we checked on October 29, 2026, for delivery to a US address.
Stock and prices on Amazon.com move without notice; the button above opens the live listing.
Prices quoted in this text were read on October 29, 2026. The live price is at the top of the page.
