10pcs: 2.5 Micron filters for face masks

10pcs: 2.5 Micron filters for face masks Activated carbon filters- 5-Layer 99% protection - 1 * Activated carbon layer + 2 * Non-woven layer + 2 * Meltblown fabric layer Filters size: 12x 8 cm/ 4.7 x 3.1 inches. Suitable for Many Occasions: Anti airborne particles dust, smoke, pollution, ash, gardening pollen and so on