Now selected as a Wirecutter pick! Small in size but mighty in power, this four-stage filtration air purifier combines a pre-filter, an odorization filter, a true HEPA filter, and a bipolar device reduce contaminants in the air.* The unit also employs a filter-change indicator, energy-saving eco mode, automatic speed control based on particles in the air, and an intuitive air quality indicator. The AP-1512HH can generate and maintain pure air in rooms up to 361 square feet, the size of a typical bedroom.