Specification: Material: activated carbon, breathable fiber cloth, non-woven fabrics Colors: Grey&white Product size: 12.5 x 8 cm/ 4.9 x 3.1 inch Quantity: 60 pieces Suggest replace the fliters every week of uses for the best effect. Multi-layer protection allows you to avoid contact with bacteria, dust, haze, car exhaust, and pollen. Package includes: 20 x Activated carbon filter Warm tip: The mask filter replaced steps: 1. Open the mask to expose the interior of the filter valve. 2. According to the OPEN directions on the valve, turn the valve counter, to separate the valve. 3. Remove the filter. 4. Replace the new filter, iterate the above steps, rotation of the valve, over.