The only mask you will ever need to protect you from COVID, other virus and bacteria. The unique properties of the INTERCEPT polymerized copper structures create a barrier against bacteria and viruses. Viruses and bacteria adhere to the inner layer of the filter which kills them on contact. INTERCEPT filters do not release copper ions. The CU22 polymerized copper laminated filter is double sided so it not only protects others from you but also protects you from others.