Bionaire BAP520-NUH HEPA-Type Tower Air Purifier with additional Performance Plus Filter Quiet Operation: The low motor setting, advanced fan blade, and specially designed true HEPA filters allow continuous quiet operation without interruption Multiple Speeds: Choose from three cleaning speeds to keep indoor air fresh and pure. Clean, Filtered Air is distributed into the room with a fan to improve air circulation Optional Ionizer: Negative ions bind with airborne smoke, dust and pollen to form larger particles that are more easily captured Slim Tower Design: Space-saving, slim design fits well in most spaces