Auto shutoff when empty</br>Illuminated power switch</br>Room size: medium?? runs up to 24 hours per filling</br>Visible cool mist</br>1 gallon tank capacity?? Kindly refer the user manual given below for troubleshooting step.</br></br>Product Description</br></br>Honeywell Cool Mist Humidifier in Black. No Filter Required. Ultra Quiet Operation. Variable Moisture Output Settings.</br><br/>http://www.amazon.com/gp/product/B00NO06VIS