Universal mask liners are made from a soft and absorbent polyester-cotton interlock fabric blend that creates a soft barrier between the skin and lining of the mask. These are great for: reducing skin irritation, redness, and unsightly mask pressure marks; absorbing oils, sweat, and saliva that can degrade the mask cushion and create leaks; and muffling air leaks and overall mask noise. The elastic band is sewn into the liner ensuring a snug fit around the mask that stays on until you are ready to take it off. Liner holes can be easily cut to fit your unique mask and facial features. Machine washable. 4 reusable liners per package.