LEVOIT Air Purifier LV-PUR131 Replacement Filter, True HEPA & Activated Carbon Filters Set, LV-PUR131-RFExtra Replacement Filter will be Restocked Until 10th January.Certified Levoit Products Designed specifically for the Levoit LV-PUR131, these certified Levoit brand replacement air filters allow you to keep producing fresh air for your home. Replacing the Air Filters To replace your the air filters in your LV-PUR131 air purifier follow the steps below: 1．With the air purifier off, unplug the air purifier and remove the back cover 2．Remove the old air filters and properly dispose of them 3．Unwrap the new air filters. Place the Activated Carbon filter inside the housing first, making sure the pull tabs are facing the opening 4．Install the True HEPA filter into the housing; make sure the pull tabs are facing the opening. 5．Replace the back cover onto the housing 6．Plug in and turn on the air purifier. Use a pen or a pencil to press the black reset button inside the vent on the side of the air purifier. The "Change Filter" symbol should now be off Be sure to also clean the dust sensor on the side of the air purifier using a clean cotton swab When Should I Replace My Filters? The air filters can be used for up to 6 months, depending on how often your air purifier is used. If you need additional help, feel free to reach out to our helpful Levoit support Package Contents1 x Fine Preliminary / True HEPA Filter1 x Activated Carbon FilteLEVOIT Air Purifier LV-H132 Replacement Filter, H13 True HEPA and Activated Carbon Filters Set, LV-H132-RF (2 Pack)Fine preliminary filter - Captures large particles such as pet fur, pet dander, lint, fibers and hair. True HEPA Filter - Filters small particles such as dust , mold spores, and allergens such as pollen, pet dander and mites. Activated Carbon Filter - Adsorbs unwanted odors and fumes such as pet odors, cooking smells smoke, ammonia and VOCs.