A "well-fitting mask" is one that...

...provides adequate cover of one's face, neither being too small nor too large :drake_dislike:

...seals to one's face, completely encircling the nose+mouth such that no air can bypass the filtration material :drake_like:

#MaskUp #BetterMasks #MaskMeansRespirator #N95OrBust #P100IsEvenBetter #FitTestingForAll