How to identify which toilet seating washer to buy?

[Mateus]

1) Flush Valve2) Back of the Flush buttons3) Seating Washer

Good afternoon, friends from Bunnings Warehouse!

My toilet has a leak from the cistern to the toilet, which I believe can be solved by replacing the seating washer.

However, I do not know exactly what brand and model to buy. The brand of my flush valve seems to be WDI, however, I could not find any seating washer of this brand on the Bunnings website.

Picture #1 shows my flush valve.
Picture #2 shows the back of the discharge buttons, where it is written "WDI K4020".
Picture #3 shows, in close, the seating washer where it shows a code: "R07".

An important piece of information, which I find important to register, is the measures of seating washer:
- External diameter: ≈6.5mm
- Internal diameter: ≈3.5mm
- Thickness: ≈0.3mm

As I mentioned earlier, I found several brands/models on the Bunnings website, but I'm not sure which one(s) could replace the one I have.

Perhaps, some of you could tell me which seating washer could properly fit my flush valve model (even if it's a generic brand).

Thank you all,
Mateus.

[Jason]

You might like to take advantage of the Bunnings toilet installation service @andrewt148.

Jason

[andrewt148]

I was definitely thinking this too. Cheers!