This is the Signal System - HO Scale Type G 3-Light Signal - Single Target from Atlas.
The HO Scale Signal System makes it easy to add working signals to new or existing layouts. They can be used as a stand-alone accessory, or connected to one another for complete integration. Based on the common Type G 3-light signals, the models feature true scale dimensions and details, and include circuitry for North American prototype operation. Choose from a single target, double target, and bi-directional targets; single targets are also available in a four pack.
*Easy set-up No external relays required
*Scale dimensions and details
*Prototype operation circuitry
*Modular design with telephone-style cord connections (for use with multiple signals, sold separately)
*Seamless integration that grows with your railroad
*Designed to be fully compatible with the products offered by Custom Signals, Inc.