SupplyAID 5-ply Foldable Mask with Exhalation Valve is suitable for adults’ daily travel protection. The KN95 mask is not to be used as a replacement for gas masks or as a medical mask. The mask cannot generate oxygen and should not be used in hypoxic environments. When used properly, the mask provides filter efficiency and the one-way exhalation valve blocks particles upon inhale and releases air upon exhale. Use this mask to protect against dust, pollen, microorganisms, and air pollution. Mask should be stored in a dry and ventilated location 23ºF - 122ºF (-5ºC - 50ºC, relative humidity <80%). Contains 10-face masks.Please check for air tightness after wearing the mask. Check to ensure the mask is tightened securely to the face. Position the protective mask gently with both hands and be careful not to disturb the mask’s seal across the face. To test for air tightness, exhale sharply through the nose. If you feel air leak from the nose piece, adjust the nose clip accordingly. If you feel air leak from the edges of the mask, re- position the ear bands. Color: White.