50 pcs 3 layer disposable protective face mouth masks anti pm2.5 facial dust-proof

50 packs disposable masks three layers of non-woven masks middle layer is bfe99 meltblown cloth product name: disposable mask domestic testing standards yy / t 0969-2013 international testing standard: astm f2100 product structure: it consists of outer layer, filter layer, inner layer, plastic nose clip and mask band. product specifications: the size of the mask is 18 5% in length and 9.5 5% in width; when folded and tiled, its width is 17 5% packing box: 21.5 * 12....