Mask 10pcs(no any filters). Advanced silicone material, comfortable fit, suitable for long time wear. Advanced headrest design, adjustable headband for a more comfortable experience, wearable with hard hat. Snap-on assembly design, can be used with 2091 particulate filter cotton and 6000 series filter cartridge. Wide application and strong applicability. Unique exhalation port, downward design, does not affect the line of sight. Conditions are rich, use worry-free. Products get multiple national certifications. Cold flow exhalation valve for smoother breathing.