The Vicks Cool Moisture Humidifier helps you breathe better and sleep more comfortably for everyday comfort. Its patented germ killing technology kills up to 99.9% of virus, fungus, bacteria and mold in the unit's water after 2 hrs of continuous use on high1. This provides the assurance that the moisture the humidifier emits is virtually free of germs*. UV technology kills up to 99.9% of bacteria, mold, fungus and virus in the units water Self regulating evaporative system adjusts output for maximum comfort Quiet Operation won't disturb sleep, For use with Vicks VapoPads Simply add a menthol (VSP-19) or Sleepytime (VBR-5) scent pad for soothing scent Runs up to 24 hours per filling 1 gallon water tank Designed for large sized rooms 3 year limited warranty Use with replacement filter WF2 *Based on independent laboratory testing report. Test No. 3163185COL-001. Results are based on the reduction of the following: Kills up to 99.9% of listed bacteria, mold, fungus and virus that exist in tap water -a. E.Coli: 99.9% after 2 hrs of continuous use b. P. citrinum: 99.9% after 2 hrs of continuous use c. A Niger: 99.9% after 2 hrs of continuous use d. MS2: 99.9% after 2 hrs of continuous use.