Elite Allergen Reduction Filter, MPR 2200, 20 x 30 x 1-Inch, 2-Pack Designed with Filtrete Brand 3-in-1 technology from 3M to pull in and trap unwanted air particles while letting clean air flow through Captures micro-particles including: PM 2.5 air pollution, exhaust , soot, smoke, cough/sneeze debris, bacteria and viruses, lint, dust and pollen Electrostatic air filter with Microparticle Performance Rating 2200 5 times better small particle capture compared to non-electrostatic pleated filters for the capture of 0.3 to 1.0 micron particles. Lasts up to 3 months