Summary

Sidewall mount for HEPA filter. I used this on my printer enclosure to allow airflow via vent while limiting dust ingress. The filters are around USD$2.50 each on Amazon (https://www.amazon.com/dp/B0CYC7M89V?ref_=ppx_hzsearch_conn_dt_b_fed_asin_title_1&th=1).
Unfortunately because of the retaining lip, during printing you'll need support all the way around. Use organic supports and limit to print bed and they should be easy to remove. Fusion file included if you wish to modify.