I couldn't find a HEPA filter cover I liked or that was on the outside. I didn't like to have the filters inside the printer so I created a filter cover for HEPA filters i use “HEPA Filters Replacement Fit for I-LIFE V3s V3s-pro V5 V5s V5s Pro Robotic Vacuum fit for Robot Vacuum Cleaner”
https://www.amazon.com/dp/B09SZ2ZJY7?ref=ppx_yo2ov_dt_b_fed_asin_title
Uses 1 screw from the back of the printer and three (3) 10x2mm magnets to hold the cover in place
https://www.amazon.com/dp/B0753ZPBLQ?ref_=ppx_hzsearch_conn_dt_b_fed_asin_title_3&th=1
Does not interfere with the poop chute I designed:
https://www.printables.com/model/1292144-poop-chute-for-kobra-s1-combo-right-side
Printed in PLA
The author marked this model as their own original creation.