This is a reusable filter case for the IKEA. Activated Carbon pellets needed and an Air filter.

Here some examples:

Activated Carbon: https://www.amazon.de/dp/B095PZLXPQ

Air filter: https://www.amazon.de/dp/B086PFYJZ7

1. Fill the activated carbon into the honeycomb slots.
2. Cut the air filter to match the case surface
3. Slide the lid on top of the filter