The EcoTech Marine RMS Track you choose is determined by the length of your aquarium. It provides a wide range of lengths ranging from 20.5 inches, to 90.5 inches long. This adjustable rail will mount multiple lights above your aquarium, providing you with an excellent solution to present the best lighting for your setting. With a black, sleek and carefully made design, your aquarium setting will stand out beautifully in any room. Attach the RMS Track to the RMS Arms or to your Hanging Kit Cables.