MEMPHIS GRIZZLIES Team Cloth Face Mask. Professor Bertrand Dautzenberg - an expert in lung disease, is very satisfied with this type of mask introduced on Afnor's site: a simple rectangle, no seam in the middle, folds and covers. both the nose and the chin.
The fabric of this mask must be waterproof and not too thick: if you see through the light and see nothing behind, the fabric is too thick, but if you see the hole where the light penetrates it is too sparse!