These black circular LED bases are about 3.5 inches wide and shine seven colors of light into a custom-cut-and-engraved acrylic plate. As my original custom product, thousands of vibrant signs have shined rainbows into homes, businesses, nonprofits and many more spaces around the world. The base can be powered with three AA batteries or by plugging the included microUSB cord into a power source. It can be activated and change colors with the included infrared remote or by touching the power symbol button on top of the base.