The Vicks V3100 CoolMist Humidifier gives you comfort and relief from coughing, chest congestion and sore throats so you can sleep better. It has 2 speed settings that let you control the mist output. This evaporative cool mist humidifier can run for up to 18 hours at a time and has a 1-gallon water tank. Its KAZ WF2 filter removes minerals and pollutants from the water. This 1-gallon humidifier is designed for rooms measuring between 800 and 1000 square feet. Its reservoir is easy to refill and it has a see-through design so you can tell when a refill is necessary.