General description The 40 Sheet 28 Inch x 12 Electrostatic Filter Cotton is designed to enhance air quality by effectively isolating particulate pollutants as small as 0.2μm. With a dust filtration efficiency of over 95% for particles of 0.5μm, this filter significantly extends the life of your air purifier's HEPA filter, reducing replacement costs and improving overall performance. Technical specifications Dimensions: 70 x 30 cm Material: Cotton Wind resistance at 0.5 m/s: 3.5 Pa Filtration efficiency for 0.5μm particles: >95% Compatibility and accessories Compatible with Mi Air Purifier 1/2/Plus Can be cut to fit air conditioners, electric fans, and other air circulation devices Installation Place the electrostatic filter cotton in front of the HEPA filter to enhance its lifespan Can be tailored to fit various devices as needed Usage Washable 1 or 2 times; avoid hard rubbing Can be used in modified air purifiers, household air conditioners, fans, and exhaust fans Other information