It was too thin. Sorry. Although I bought it for stress relief of the ear hook, it is because I am using 3 layers and 4 layers, and this product is dry in winter seems to lack dustproofness in a warehouse full of dust.
Since there was a review that it was originally thin, I bought a thinness convincingly. I feel easy to breathe. However, it is not easy for the juncture of the filter and filter to break easily. Attention is necessary because it will be cut every time you take a mask with holiday time.