LightRail? moves your lights over the tops of the plants, reducing shadow patterns and getting the correct intensity of light on the leaves for optimum Leaf Area Index ? the single most important factor in increasing your yield. You?ll get much better yields plus up to 20% more area covered ? you save energy and money, and with much better results. LightRail? is the single best way to get more from your grow lights. LightRail? ? solidly made in the USA since 1986.