The flapper "installed" nice enough (there's not much to install).
But soon after, I had to fiddle with the way the "chain" hooks up. (I no longer recall why, but almost certainly I had to fiddle for the same reason this plastic "chain" continues to curse itself) Soon, the stainless clip snapped (!?) I substituted a short piece of copper wire.
But once every few months, the middle part of the plastic chain has floated
*above* the "clip" (while flapper is open and tank flushes) and hung-up. This holds the flapper open. This leaves the fill-valve running indefinitely, until a human being unhooks the plastic fake-o chain and allows the flapper to shut.
(I'm glad we don't live in a McMansion, else the water bill would grow huge before one of the maids reached the 9th Floor, Wing #16, and discovered the running fill valve.)
The "dial" type adjustment of the flapper is no help, because it doesn't affect chain flotation.
I may try hanging a small weight slightly above the mid-point of the chain (located to clear trouble) a smashed little ball of copper wire might work. Having to fix *new* products is annoying.
PS. The "maids" are figmentariacious. So, maybe I should have called them "McMaids"? PS2, Wing #18. Supposedly the pink colored "rubber" parts of the flapper resist chloramine, which is good.