Check the listing for details. White KN95 Improved Standard GB2626-2019 Protective Face Mask 50 Per Box. Condition: New. Listed at 9.25 USD. The multi-layer filtration system of non-woven soft and breathable fibers of the KN95 face mask is comfortable and efficient. These KN95 masks carry a high particulate filtering efficiency of over 95% that is also FDA approved, making them excellent in protecting against viruses, dust, bacteria, and any harmful airborne substance. Made with a flexible metal fastening strip ensures optimal sealing between the bridge of the nose and the mask that helps maintain a smooth filtered breathing experience. These KN95 masks are produced in very clean, almost dust-free production environments. The KN95 masks comply with standard GB 2626-2019 (KN95 grade), The performance is tested on four sections:1. Tested using NaCl as the particulates, the flow is 85L/minute, the density of particulates: 15mg per CBM, at regulated temperature range, and at regulated humidity range. Filtering efficiency comes in over >95%.2. Resistance to inhaling (air in): must be less than 350 Pa.3. Resistance to exhale (air out): must be less than 250 Pa.4. Quality of earloop/headband straps: pulling force of 10N lasting for 10 seconds, cannot break and remain intact.