One of our toilets stopped working reliably – the culprit seemed to be the valve that fills up the top tank (AKA the fill valve or flush valve), as it wouldn’t consistently open to fill the tank after flushing. This water-saving valve seemed like a good choice and it’s inexpensive to boot. Installation was easy, involving just a quick shut off of the water supply to the toilet, unscrewing the old valve and threading in the replacement. The water-saving aspect is interesting – there is a small valve to adjust the rate at which the bowl fills, with the idea to get it filled at the same time as the tank. Apparently with a conventional system, some water is wasted as it overflows the bowl before the float rises in the tank to turn off the valve, It works great so far.