Here is the web site
I used something like this for a while with the 1.0 gpf flush.
The cartridge tended to leak past the seal, so turning it off at the wall help to save some of the wasted water.
I seemed pretty plug resistant. Bowl cleanliness was a problem.
They say on their page that it was Extra-Quiet.
Quiet compared to what? I thought it was noisy.
Inside looking at the Flushmate tank.