[Quality]: Made of high-quality activated carbon, non-woven fabric and melt-blown filter cloth, it can effectively filter out 99% of exhaust gas, pollen, smoke, dust, chemicals, particles and soot. [5 layers of protection]: The first layer of cloth filters out micron dust. The second layer filters industrial pollutants, car exhaust, passive smoking and pollen allergens. The third layer of activated carbon cloth filters out micron dust. The fourth layer provides filter density for smaller materials. The fifth layer of cloth filters out various harmful substances. [Wide application]: The mask filter is very suitable for all outdoor and indoor sports, such as running, jogging, biking, motorcycle, horse riding, hiking, skiing, snowboarding, paintball, mowing and others on public transportation activity. [Package content]: 100 activated carbon filters. Multiple protections isolate dust and provide good ventilation. By inserting an additional filter in the dust cover, the protection against harmful substances, gases and odors can be doubled. Dimensions: 12 cm X 7.5 cm / 4.7 inches X 2.95 inches It is compatible with most of the masks on the market, just put it in the mask to give it a protective effect!