LightRail 5 Auxiliary Rail This is used with LightRail 5 and a second Add a Bar Kit (AAB KIT LR5), see item R, to accommodate a 3 crossbar system. The LightRail 5 Auxiliary Rail Item is packed in a tube with installation hardware and instructions. Note: The LightRail 5 Auxiliary Rail does not have rail alignment pins and does not need them because travel across the seam will not be necessary.