CHEK YOUR DEVICES MODEL NUMBER to be sure this is the right replacement filter for your Air Purifier. The filter dimension is 11.81"x 7.52"x 7.52" compatible with air purifier models AP-T45, AP-T45WT, AP-T40, AP-T40WT, 1461901 (Costco model) APT40FL. Work just like the one that come with unit. Cost-Effective Price: Package included 1 unit filter and 30 pieces essential oil microfiber pad, save much cost for your all year round air cleaning need and aromatherapy. It is recommended to replace filter for every 6-12 months. Using an old filter and essential pad lowers your air purifier’s efficiency. Trap Household Odors: The high-grade activated carbon filter can efficiently absorb unwanted odors, fume, smoke, cooking smells, as well as filtering pet odors. H13 Filtration Technology: Genuine 5 in 1 filter 360° filtration. A higher grade H13 material, trap small particle such as dust, pollen, dander, down to 0.3 microns from the air. Higher level microfiber pad: Batter absorbent for long time diffuse using, just need to drop 3-4 drops essential oils on the refill pad, then enjoy the aroma of oil to ease symptoms of stress or anxiety.