Should be item 247747 according to the reviews of this item.
Unfortunately, the name of the item is not really as accurate as the other sizes and the manufacturer's number has changed again in the meantime.

Is this a fake question to get me to log in to Galaxus once? It's a tactic that can work, just not for me. Because the goods I bought at Galaxus are top-notch and I don't need anything else at the moment.

You can find Bialetti sealing rings at Galaxus, Manor and many other retailers. Specify the diameter and you will receive precisely matched rings from Bialetti in a pack of 4.