I like this fill valve very much. I have installed its "sister" valve, the regular (white color) 528, on several older-model toilets. (This blue-color 528T has a higher refill percentage than the regular white 528 and thus is proper for Toto G-Max toilets. If, instead of a G-Max, you have a Toto 1.28gpf Watersense-eligible toilet [also known as Toto E-Max or "Eco" or has "E" in its model number and a green-colored valve inside], then you should buy the (silver color) 528MP which lets you adjust the refill percentage to the exact amount your Eco Toto toilet requires, as confirmed by Toto customer service.) That said, this valve WILL work on an E-Max toilet in the sense that it will sufficiently-fill the bowl; however, you will no longer be using 1.28 gallons per flush because this will put too much water into the bowl on refill, and that water will simply drain away; so, you'd be wasting water. This valve shuts off with no water hammer or definitive noise. The water just stops flowing. I like that. I also like the relatively-quiet rush of water when it is filling. I also like the fact that when the internal diaphragm that controls the water flow wears out in about 5 years, you easily can purchase the replacement diaphragm cap for a couple of dollars locally or on Amazon, and just swap that out without having to buy a whole new valve. Toto buys original equipment made-in-the-USA fill valves from Korky (Lavelle Industries is the manufacturing company of Korky-brand products) and installs them in Toto toilets. Toto also buys different-looking fill valves from what I understand to be a foreign manufacturer. If you buy a G-Max toilet, the brand of fill valve Toto preinstalls in your tank will depend upon what country the tank is manufactured in. The Toto Drake tank, for example, is manufactured in the US, in Mexico and/or other locations. On one of my Drakes, Toto had installed the 528T (with a Toto OEM part number and a cap that says G-Max instead of Korky), which is made here in the US by Korky/Lavelle. On the other, they had the foreign valve, the one with the adjusting screw. That valve, when working properly, emits a squeak or chirp or sharp "Zhoompf" when the toilet is full. (I have a Toto Carlyle with the green E version of the foreign valve that does the same thing.) I personally find it annoying. Indeed, I found the noise so annoying that I bought this 528T from Amazon, ripped the foreign valve out, and installed and adjusted this one in less than 5 minutes. Now both of my Drakes fill and shut off quietly. The two most popular fill valves in the US are the Fluidmaster 400A (and versions thereof) and this Korky 528 (and versions therof), both sold as Original Equipment parts and replacement parts by different toilet manufacturers. So this is an excellent, widely-used valve. Toto does not use the Fluidmaster 400A as original equipment, although Fluidmaster now makes a version of the 400A that has an adjustable refill rate so that it can be installed in Toto toilets as a replacement (but only that version.) The 400A is an excellent valve that plumbers swear by, but is noisier than the 528 and more of a pain to adjust. The shutoff, however, is just a nudge louder than the 528, essentially a quiet hiss. The foreign valves that Toto is using are substantially-noisier on shutoff and really would be my last choice as a replacement part. In the end, I really think this 528T is the best valve for Toto GMax, and the 528MP is the best valve for Toto 1.28gpf toilets. One other note: a lot of folks seem to be confused by the anti-siphon action of the Korky valve. This is a feature that keeps it from sucking tank water back into your drinking water supply. For it to work properly, a small amount of water will flow from the valve housing near the top. The excellent instructions make clear that this is NORMAL, but I have seen so many people complain that the valve is "broken" or "leaking" because it does this. Fear not. If you see this when watching your great Toto toilet work, don't give it a second thought. One other thing: we all understand, don't we, that low-flow toilets are NOT supposed to drain all the water in the tank on each flush. Filling the tank to the Toto-specified level is important, because the weight of all that water that isn't going to flush pushes down on the little bit of water that will be flushing when the flapper opens for only a second. The weight of the tank water drives the flush water through the valve quickly, leading to that great, effective flush that we all love. A video of the proper operation of the tank components is available on you tube if you search for "Toto Drake CST744S GMax Tank View of Flush". The video features the OEM version of the 528T fill valve featured here, and the OEM Toto flapper, on a toilet that is about two months old.
