Select non-woven, filter large particles, protective layer, effective to filter particles, moisture absorption non-woven fabric, soft, comfortable breathe freely, three-dimensional design, in line with the facial contour curve, fold edge design, ear more fit, high elastic elastic design, more fit to wear comfortable is tight, three layers of folding design, large space more comfortable breathing, three layer filter effectively block the air in the tiny particles, low resistance, don't breath, uniform surface porosity allows you to enjoy referral to breathe.