I have one similar to this one. Here is the cold brew container that I have used for a year now. That and a 20 oz mason jar, which I pour the brewed coffee. I like keeping one brew ahead, if possible.

As far as the coffee I have been experimenting with, here is a Big Lots coffee that I have been using that give a pretty decent yield for the price. However, nothing beats the yield from a freshly coarse ground coffee bean, if you can find them at a decent price.

https://preview.redd.it/5qhcdofa3hba1.png?width=3024&format=png&auto=webp&v=enabled&s=0c4d59c72ef88a93ae6a4ce559d2b3c02234d85b

Is it this silicone ring? Could you measure the diameter?

I have a spare from this similar-looking brewer, from when my glass old carafe broke: https://www.amazon.com/dp/B071ZWR7M8

I could send you mine if the diameter is the same.

Diameter of filter top: ??

Diameter of filter bottom: ??

Diameter of glass carafe mouth: ??