13 layers of the muffle pad, surface waterproof layer, middle isolation layer, skin-friendly layer inside. 2Comes with 10pcs muffle pad of the package, individually packaged, safe and hygienic, suitable for multiple kinds of mouth muffle. 3Large surface area to ensures smooth breathing and not stuffy, comfortable for long hours wearing. 4Based on the human face engineering three-dimensional structural design, close fitting your face. 5Suitable for filtering the particulates in the air, blocking droplets, blood, body fluids, secretions, etc.