Linking photo
Suggestion from 
minami4ffp3 on Jan. 25, 2022, 8:01 p.m.
Linked webpage with a photo of a surgical mask covering the North 7700 exhalation valve. Would have uploaded the picture here but didn't email for permission.
Changes in this suggestion:
minami4ffp3 authored on Jan. 25, 2022, 8 p.m.
Comment from
philipn on Jan. 25, 2022, 8:14 p.m.
Thanks, accepted! 💫