Sandistore Activated Carbon Anti Dust Mask Bicycle Motorcycle Racing Ski Half Face Mask Military design mask provides excellent filtration against most type of pollution, an urban cyclist is likely to encounter included pollens, dusts, vehicle fumes and bacteria The filter is replaceable, and is designed to be effective at least 3 months in normal daily use The filter is replaceable, and is designed to be effective at least 3 months in normal daily use Includes two one way valves to allow easier exhalation of heat, water vapour and Carbon Dioxide, suitable for glass wearers Size:Length:50 cm(Approx) Width:13 cm(Approx) Material:Cotton