Luminglas plasma discs are wonderful light toys that react to your music and touch with a lightning effect. Most of them are round, measuring from 3 to 20 inches. These Blue & Green Square Luminglas Flat Plasma Lamps are much rarer. They measure 16 inches. They were made in red, green, blue, and other colors.
These lights have a panel in the back that let you adjust pattern and sensitivity.