Adults PM2.5 Activated Carbon Filter Face Mask Anti-smog PM2.5 Mask 5 Layers Replaceable Anti Haze Filter Breathing Insert,Dust Mask Replacement Filter Paper for Mouth Mask 100 PCS

The mask filters works great.I use it when walking and biking in dusty areas and find that it blocks enough dirt to avoid having my sinuses irritated.But not each mask can be suit,depend on your mask size.