Sale ALL scale Atlas HO Atlas HO/N 70000047 Railroad Signal System - Interlock Control Module Atlas HO/N 70000047 Railroad Signal System - Interlock Control Module The Atlas All Scales Signal System enables you to provide realistic information to your train crews in a simple, yet expandable way. Our growing line of signal heads, masts, and... $36.95 $25.99 Add to Cart Add to Wish list Compare