Received slightly different item than description. Item that came is labeled as from the makers of Korky, and is listed as a Lavelle Industries brand on the back. This isn’t a big issue, as Levelle does make oem parts for manufacturers. Interestingly enough, it has TOTO printed right on the part.

It appears to be similar to the original with a few changes.
-they eliminated the rim at the edge, and added some support columns off the center section. This hopefully will prevent some of the cupping seen in the last photo.
-the chain sleeve is missing, which i just transferred from the old part. This sleeve helps prevent the chain from getting bound up when it’s in the resting position.
-the hook type is different, so follow the guide on the back of the package regarding chain placement. I think it was one or two less than original.

I came across this part by looking for original part number for my toilet model ST743S, which was THU175S, replaced by THU331SS, then replaced by THU499SS which is the universal catch all number. Reviews for that universal part suggested that manufacturers had changed, quality had dropped and problems were common. This part was suggested by someone’s contact to tech support to match the original part by the original third party manufacturer.

Installation was successful with no leaking. Will update with any problems.

Don’t waste your time. I have 4 Toto toilets (1 Carlyle, 3 Ultramax) for 10 years now. The flappers have been an intermittent pain throughout, sometimes they last, sometimes they leak within weeks of being changed. It varies by toilet (even of the same type). No brand of replacement flapper seemed to work reliably better than any other. I wondered how most newly installed toilets in hotels had tanks built into the wall – with so many toilets to maintain surely they couldn’t be changing flappers at that rate. Nobody uses flappers anymore on good new toilets – they use drain valve towers instead. A new tower (for 1.2 Gpf) has been working well on one of the old 1.6Gpf Ultramax (search for THU460.15E-A, available on Amazon site). Very easy to fit (just need Phillips screwdriver), though a little tedious altering the fill height to match. For the Carlyle I stuck with the 1.6 GPf (THU453.10.C-A).Harder to find but got them from plumbing supply.com (a couple of weeks for special order, but very helpful). Again easy to fit, and I used that drain valve agin for the other Ultramaxes (no need to play with fill level this time). All working well, and am glad to be free of the whole flapper nonsense.

So your first question might be how do I figure out if this fits my Toto toilet? To figure out your model number, take the lid off your tank and look at the bottom. You should see an alphanumberic starting with either “ST” or “CST” followed by 3 numbers. Thats your model number. Check this against the part compatibility info to see if this works with your toilet.

So far as the flapper, I actually got the first one from my local Ace Hardware because I didnt think to check Amazon, silly me. I’m buying the second one from Amazon.

I installed the original one and it fit perfectly. It does indeed come with the chain, and the documentation it has says its guaranteed for 5 years. I shot an email to the manufacturer to see exactly how it works so I’ll update my review when they respond. Why only 3 stars? I’m withholding a perfect review until I hear back on the guarantee.

Update: Got an email response from the manufacturer, Lavelle Industries. Based on the below, this feels like a no-brainer…5 year guarantee at half the cost of the Toto-labeled flappers.

[Response from Lavelle Industries]

“Thank you for contacting us, and for purchasing our Korky product!
There is no need to register the flapper. Simply keep our number on hand along with the flapper model number. If in the event you do need to replace the flapper, give us a call and state you need a warranty replacement and we will be glad to send one your way.”

I have 6 TOTO toilets in my house. Great toilets, except for the flapper valves. I have been purchasing the 2023BP Universal Flapper Valve but still wasn’t getting good long-term results. I called TOTO technical support and read them my flapper valve numbers from all the toilets. The tech explained that while 2023BP was a universal replacement, the 2021BP was the OEM replacement for my THU253S, THU275S and THU331S flappers. He is also sending spacers for the flush valve arms where the ears of the flapper valves attach. The spacers keep the flapper valve centered in the tank. The spacers are free if you call tech support.