The HEATDAZ MR5866 air purifier replacement filters are designed to be perfectly compatible with the MR5866 Air Purifier. It guarantee certified fit and optimal performance, unlike off-brand filters that may fail HEPA testing standards, fit incorrectly, reduce efficacy, and cause damage to your air purifier. The unique dual side air intake design allows for faster purification speed and effective capture of pollutants from all directions. The upgraded filtration technology includes a layer of electrostatic cotton that intercepts larger particles and absorbs more odors, achieving higher filtration efficiency. The two-piece package comes with two genuine HEATDAZ original true HEPA filters, offering significant savings on annual air cleaning needs. Installation is easy, requiring no tools, and can be completed quickly. Before replacing the filter, ensure the power key is turned off and the old filter is removed. After installation, turn on the power, press and hold the filter button for 5 seconds until you hear 3 beeps to complete the reset of the filter indicator light.