AirQueen Nano Mask is made from Nanofiber Filter manufactured from advanced nano-technology. Nano fibers are only 1 nanometer, 1 billionth of a meter, in thickness. Nanofiber is a new material made by building these fibers sterically for a fishnet structure that has better permeability, blockability, and durability than any fiber ever invented. AirQueen Mask has a high level of filter performance and has been found to have excellent ratings in both inhalation and exhalation resistance, making it easier to breathe through while maintaining a high filtration rating. When compared to traditional electrostatic fiber, the Nanofiber Filter is much thinner and has much tighter spaces between fibers for superior filtering performance. More importantly, Nanofiber mask can be reused. Simply spray the mask with ethanol and allow to dry after each use. Filtration efficiency will not be affected even after 10 uses while traditional electrostatic fiber filter see a 64% drop in filtering performance when they are reused. Each item is individually packaged. The manufactured date is printed on the pack. Expiration is 3 years from the date of manufacture. Additional Details ------------------------------ Product description: AirQueen Nano Mask is made from Nanofiber Filter manufactured from advanced nano-technology. Nano fibers are only 1 nanometer, 1 billionth of a meter, in thickness. Nanofiber is a new material made by building these fibers sterically for a fishnet structure that has better permeability, blockability, and durability than any fiber ever invented. AirQueen Mask has a high level of filter performance and has been found to have excellent ratings in both inhalation and exhalation resistance, making it easier to breathe through while maintaining a high filtration rating. When compared to traditional electrostatic fiber, the Nanofiber Filter is much thinner and has much tighter spaces between fibers for superior filtering performance. More importantly, Nanofiber mask can be reused. Simply spray the mask with ethanol and allow to dry after each use. Filtration efficiency will not be affected even after 10 uses while traditional electrostatic fiber filter see a 64% drop in filtering performance when they are reused. Each item is individually packaged. The manufactured date is printed on the pack. Expiration is 3 years from the date of manufacture.