Feature: Unisex adult face mask The reusable washable cotton mask One size fits all with an adjustable hook strap Filter breathing valve for comfort Includes 1 PM2.5 carbon filters Easy installation of filters Plastic nose bridge adjustment for a custom fit Clean & Care Instructions: PM2.5 Filter can NOT be cleaned and must be replaced. Recommended Bi-Weekly. Clean the Outer Face Mask with a neutral detergent. Hang dry to finish cleaning.