Wearing a mask while you have a contagious sickness can help prevent it from being passed on to other people. Free N95 masks costco N95 mask free before applying mask, wash your hands. NIOSHlist NIOSH approved N95 Harley pay for your order at the checkout. When it is over, it will be time to replace it. How can you be sure that the products you buy on Amazon are real? Then you've already experienced how great they are.