EFFICIENT THREE-STAGE FILTRATION SYSTEM: PARTU HEPA Air Purifier features a three-stage filtration system. This comprises a pre-filter, a HEPA filter and an activated carbon filter, powerful enough to captures up dust, pollen, smoke, odor, pet dander, filters particles as small as 0.3 microns and air pollution of PM 2.5.. AIR PURIFIER WITH FRAGRANCE SPONGE: Add a drop of essential oil (Not Included) and some water into sponge below the purifier air outlet, then fragrance will flow with air movements. (Such as Citrus, Honeydew Melon, Musk, Vanilla, Orris or Vetiver). LOCK SET: It’s efficient to avoid error operation caused by pet or child’s during their curiosity. (Keep pressing the Lock button for 3 seconds to start avoiding touching mode.) Three fan settings let you control the speed and volume of the Air purifier.. BLACK CASE AND SLEEK DESIGN: Compact enough to fit on your desk. Effective area 107sq.ft/ 10m (bedroom/ office). Noise Level :38-59 dB. 12 Watts; 0.8 A; Better suited to small rooms than large homes. (A voltage converter is needed if you want to use this air purifier beyond the US.). IMPORTANT: The replacement filter should be replaced every 3-6 months depending on the air quality in your area and use of the Air Purifier to ensure best results. Easily obtainable under 25 dollars with the replacement filter (Search for: B07KY5WZVQ). Note: please remove the plastic bag of the HEPA filter and charcoal filter before running the air purifier.