Qiorange Outdoor Sports Mask Filter Air Pollutant for Bicycle Riding Traveling Open-air Activities Protective Universal Easy replaceable filters. Designed with a non-woven cloth, filter to screen out air pollutant like dusts and vehicle fumes. Replaceable and washable filter, and is designed to be effective for at least 3 months in normal daily use. Designed with two one-way valves to allow easier exhalation of heat, water vapour and Carbon Dioxide,suitable for glass wearers. Aluminum lock, help to fit the mask onto nose stably, Made of SBR to give a comfortable and secure fit.