About This Item: [Filtering Efficiency] ≥ 95%]Our high-quality electrostatic filter cotton has higher adsorption capacity and low respiratory resistance, which can better defend our respiratory health. Respirator cartridges cotton a wide range of nonoily particles such as dust, PM2.5, pollen, welding fumes, etc. [Recommended Usage Time]The particulate filter cotton generally lasts 8 hours. When the filter cotton is damaged or dirty, has a strange smell, or has significantly increased respiratory resistance, you should leave the contaminated area promptly and replace the 5N11 filter cotton. .