Upgraded Version Silicone 3D Mask Bracket Quantity:3PCS The key difference here is

The key difference here is that during adsorption the pollutants stick to the outside of the carbon

filter material: non-woven fabric

I believe you will like it

U-shaped back

Upgraded Version Silicone 3D Mask Bracket Quantity:3PCS The key difference here isHigh quality Material: Face frame support bracket made of food grade silicone material, soft, smooth and comfortable, washable, and reusable. Expand SpaceThe bracket holds up the fabric around the mouth to create more space. Protect Female makeup, do not stick lipstick. Patent design: Unique wearable design, soft fit face, will not fall off. Full of elasticity: It can be folded at will without deformation. Easy to carry.