The Xiaomi Mi Air Purifier HEPA Filter is designed to eliminate 99.97% of particles as small as 0.3 microns from the air. It works in conjunction with the Xiaomi Air Purifier to get rid of harmful bacteria. This true HEPA filter is designed for air-born dust, cigarette smoke, pet dander, mold spores, pollen, germs, virus, and odors. When combined in a 3 stage filtration system, the pre-filter, HEPA filter, and activated carbon work well together to capture particles and odors in the air. Its tower-shaped cylinder design helps circulate the air more effectively. The Air Purifier HEPA filter helps to purify the air while having a 3 to 6 months life span.