Have 2 of these pieces of cr*p installed (sorry about pun). Never again would I buy something like these. The flappers stopped working properly after a year. Replacing one flapper only stopped the problem of "phantom flushing" but did not stop the "running on" problem. Both toilets have the running on problem after a year or two. One is the dual flush model, the other is a single flush model.
Also the seats have never fitted properly and constantly slide all over the place, giving worrisome thoughts to males in the house.
The sad thing is, it is hard to return them after you spent all the time & effort in installing them and using them for a while.
Spend some money on more than an $80 toilet and then spend your time doing something useful, like having fun or making money, instead of repairing new toilets. Visit a real plumbing store please.
The most depressing thing about this is that the lovely also bought 4 of these cheap things for a country home we're building.....