It is linked in the source.... https://bmjopen.bmj.com/content/5/4/e006577.long https://bmjopen.bmj.com/content/5/4/e006577.long Penetration of cloth masks = 9

It is linked in the source.... https://bmjopen.bmj.com/content/5/4/e006577.long https://bmjopen.bmj.com/content/5/4/e006577.long Penetration of cloth masks = 97% Penetration of N95 = 44%