Himalayan Pyramid USB salt lamp Material: Wooden Base + Crystal Rock Light Color: Green, Yellow, Blue, Purple, Red Size: 4 x 2.5 x 2.5 Having a Himalayan crystal rock salt lamp at home helps in keeping a balance between the Electromagnetic Field around you, thereby maintaining a healthy environment. These rock salt lamps are uniquely shaped with the salt crystals from the foothills of Himalayas. Keeping them beside heavy electrical gadgets like television, refrigerator or air conditioners will keep the essence of natural air intact. Operation: Just connect the USB to outlet charger, computer or PC, it will work and the color of LED Light will change automatically.