For anyone coming here late, the items posted by /Tigertron62 do fit perfectly. At the time of this writing, they are not Prime and mine took 2 weeks or so to arrive.
Here is the link again:
https://www.amazon.com/dp/B097M5BWHH
I bought this and they work fine
Sunnym Side Brush HEPA Filter... https://www.amazon.com/dp/B097M5BWHH?