HIGH-EFFICIENCY AIR PURIFIER: Designed in NYC with love and care, the THINK BEST air purifier cleans, purifies and filter rooms up to 232 sf and circulate the air over 4 times per hour. Enjoy safe, healthy fresh air at home and improve air quality. Suitable for medium-sized rooms, like offices and dorms. 4-STAGE ADVANCED AIR FILTRATION: Pre-Filter, True HEPA filter, Active Carbon Filter, Natural Ions mode; captures and reduces up to 99.97% of particles 0.3 microns in the air, including pollen, molds, dust mites, pet dander, smoke, pollutants and other allergens. It also reduces volatile organic compounds (VOCs) and reduces odors. TOUCH SENSITIVE ULTRA-QUIET NIGHT MODE: multispeed fan: 3 settings, from low (only 25dB), medium, or high mode (52 dB), NATURAL IONS MODE can be switch ON or OFF and helps eliminate airborne particle using a safe, proven electrochemical reaction that neutralizes dust, pollen, mold and allergens using negative ions. NIGHT MODE: ultra-low fan speed for restful nights and easy breathing. 2 night lights: Comfort red and peaceful blue. FILTER REPLACEMENT REMINDER. TRUE HEPA FILTERS: 9 MONTHS+ Longest lifespan of all consumer true HEPA filters, ThinkBest suggest to replace the filter every 9 months or more, depending on usage. Inexpensive replacement filters are easily available through Amazon. CERTIFIED QUALITY & SAFETY: ETL & CE Listed, CADR, this air purifier meets strict quality and performance requirements. Quality Assurance and Limited Manufacturer's Warranty of 1 year with lifetime customer support.