Salt Lamp W/usb Cord & Led Light Pyramid 3 Inches High Made of natural salt crystal from the himalayan mountains Works as an air purifier by emitting negative ions into the air and light therapy to reduce stress and increase energy Our polished USB salt lamps are the perfect computer and wireless-device companion. They reduce unhealthy electromagnetic fields (EMFs) and purify the air naturally, by emitting negative ions, which neutralizes hazardous positive ions transmitted by all modern electronics. USB cord & LED light included.