The 10K Metal Halide is used for the last 2 -3 weeks of bloom to allow better ripening and finishing. Available in 1000w & 600w Used for vegetative growth and last 2-3 weeks of bloom (finishing). Featuring Low Iron (Low-E) glass for enhanced UVA and UVB penetration to your plants for higher quality and yield! Our special low iron glass allows for more UV spectrums to get to your plants and flowers. Low iron glass is composed of purified materials free from contaminants that make the glass extra clear. Usually glass has a green tint to it, these are impurities possibly from recycled materials. It has been proven that Low-E glass allows more UV light to pass through. 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.