Activated carbon filtration PM2.5 mask anti-pollution anti-dust. Comfortable design - adjustable nose clip, ear loops and velcro behind head provide better and more secure fit with less pulling behind ears (compared to other masks with just ear loops). Breathable design - double air valve helps to breathe easier with over 95% filtration; ideal for running, cycling, etc. Non-woven mask cover machine washable (remove activated carbon filter before washing). Replace filter every 30 days or if damaged or blackened with particulate. Package includes one mask and 2 filters. One size fits most. Shipped with USPS first class. Condition is New.