Featuring premium quartz glass for enhanced spectrum and penetration to your plants which results with higher quality and yield! Why digital lighting? The Sun is high frequency. In order to make artificial light behave more like natural Sunlight it needs to be high frequency. Digital lighting makes for a higher quality of light that’s good for all living things... This is only possible if you have the proper lamp and ballast combination. STK Lamps contain UVA-UVB and the upper portion of UVC. Exercise caution when working around any HID lamp that contains UV, always wear protective lenses.