There is no single model railroad accessory that captures the essence of prototypical railroading more than an operating signal system. Whether standalone or as part of an integrated system, a working signal adds both visual and operational interest to your railroad. 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 bridges spans most common modeling eras, and are easy to install on your layout. The signals feature true scale dimensions and details, and are available in single and double head arrangements, as well as several multi-track bridge configurations. Regardless of scale, all Atlas signals now utilize a small standardized connector and separate cable to connect to the signal control boards, minimizing the impact of installation on a layout with existing scenery. The Signal Control Board can operate standalone, or as part of an integrated system to replicate the behavior of many North American prototypes, providing selectable 2 or 3 block (ABS) operation, flashing aspects, approach-only, and PRR and color position light options. It can drive either common cathode or common anode signals, and can be powered by AC or DC. The system can be used on layouts operating on either analog (DC or AC) or Digital Command Control (DCC) power through the use of appropriate block detectors (not available from Atlas), and can also be manually controlled.