This snazzy and smart Adult PM 2.5 Filtering Mask in Black looks great while keeping you covered! The outer layer is made of a tightly woven cotton that holds its shape. The inner layer is made of a soft brushed cotton layer. The inner layer has an overlapping slot that you can slip a PM 2.5 filter insert into. The mask comes with two filter pieces. https://elecena.pl/product/17502703/adult-pm2-5-filtering-face-mask-with-2-filter-inserts 2021-04-07 https://elecena.pl/product/17502703/adult-pm2-5-filtering-face-mask-with-2-filter-inserts 2024-04-16