Bundle pack of our PM2.5 6-layered activated carbon filter Made In: China Materials: 100% Cotton Care: Cannot be washed. Notes: For use with VIDA Protective Masks (sold separately). Replace filter after one week of use. Particulate matter (PM) refers to particles in the air that cause pollution. Particulate pollutants vary in size and the smaller they are, the more damage they cause to your health. A PM2.5 mask refers to a mask that is able to filter out particulates that have a diameter of 2.5 micrometers (microns) or less. Coronavirus particles are spheres with diameters of approximately 0.125 microns. The smallest particles are 0.06 microns, and the largest are 0.14 microns. These masks are not medical devices and are not a replacement for surgical or procedural masks. Using PM2.5 Mask Against COVID-19 CDC recommends wearing cloth face coverings in public settings where other social distancing measures are difficult to maintain (e.g., grocery stores and pharmacies). VIDA’s reusable masks follow all of CDC’s guidelines for protective cloth coverings with a 6 layer layered activated carbon PM2.5 filter, a built-in nose clip for a snug protective fit and adjustable ear loops. CDC recommends that face coverings - - Fit snugly but comfortably against the side of the face - Be secured with ties or ear loops - Include multiple layers of fabric - Allow for breathing without restriction - Be able to be laundered and machine dried without damage or change to shape Additional CDC Recommendations: Wear cloth face coverings in public settings where other social distancing measures are difficult to maintain (e.g., grocery stores and pharmacies). Cloth face coverings should not be placed on young children under age 2, anyone who has trouble breathing, or is unconscious, incapacitated or otherwise unable to remove the mask without assistance. Cloth face coverings are not replacements for surgical masks or N-95 respirators. Those are critical supplies that must continue to be reserved for healthcare workers and other medical first responders, as recommended by current CDC guidance. Full CDC Guidelines