The Bionaire® Aer1 True Hepa Air Purifier Tower space-saving design easily fits in any corner of the room, leaving clean and crisp air all around your home. The 4 Stage Filtration System work to remove pollen, dust, mold, pet dander, and smoke from any medium room up to 188 sq ft. The filtration begins with with a pre-filter that captures large particles such as pet hair and dust bunnies. The air then passes through the Aer1 True HEPA filter capturing particles as small as 0.3 microns to remove up to 99.97% of airborne particles. And lastly, the optional ionizer helps to bind smaller particles to form larger particles that are more easily captured. The capacitive touch control panel lets you easily control the air purifier settings – from 3 speeds to 8 hour timer. The Holmes® Aer1 True Hepa Air Purifier also features a Filter Reminder Light which combined with the VisiPure Window lets you check the progress of your filter life in real time.