UL approved for dry use only. Made in EU. Chromalux light bulbs are made of special composition glass that is not colored or coated, but instead contains neodymium, a rare earth element used in lasers. This earth element is able to absorb yellow and other dulling components of the spectrum. As a result, the light is purified, allowing the values of violet, blue, green, and red components to be strengthened, without producing an imbalance of one color over another. Due to its chromatic balance and color discriminating qualities, Chromalux full spectrum light bulbs produce glare free light that helps you concentrate longer with increased visual acuity and greater comfort. Chromalux full spectrum light bulbs reduce eye stress and create a pleasing, colorful, and relaxing environment that enhances people's sense of well being.