Data: 07/08/2020
https://www.youtube.com/watch?v=zvjLGDZTiCw
Here are tips on how to sew a three-layer fabric mask. Research has shown that this combination of materials and layers provides a higher level of breathability and filter efficiency than single layer cotton masks.
Idioma: Inglês Duração: 1 vídeo do youtube (1:14 min): son., color. Editor: World Health Organization
