1. Air-cleaning function [an environment-friendly air-cleaning function without producing ozone] 2. Humidifying function [maintaining humidification at 60 percent] 3. Aroma-producing function [water-soluble aroma (phytoncide, aroma) available] 4. What is the Lenard effect? When a fine liquid creates drops, and floating water-droplets with more than tens of millions of surplus electrons collide with particles of air, a negative ion is generated. It takes approximately 720 seconds for a droplet of one-micrometer size to evaporate without airflow and negative ions spread approximately 10 meters. On the other hand, since negative ions are generated when the electrons in an electrode collide with particles of air, the generated negative ions survive only for 25 seconds. Negative ions are too restrictive because they only spread 30 centimeters without airflow. we do welcome any question, please email me at