These color changing USB Salt Lamps are truly unique with a white Himalayan salt crystal that changes colors when plugged in to a computer or USB adaptor. Salt lamps emit negative ions, which work like natural ionizers keeping the air clean. Negative ions attach themselves to dust, pollen, mold, fungus and odors. This is known to be very beneficial for respiratory health. Salt lamps also minimize the effect of positive ions from EMF�s and electronic devices, while the natural color of the lamp reinforces the rejuvenating and healing influence.