Atlas Twin Electrical Connector which is ensures everything is connected so you are ready to run the rails. Atlas #210 Twin Connector. FEATURES: The Atlas Twin consists of a pair of double-pole, double-throwswitches internally connected to allow independent electricalpolarity control for two pairs of output terminals. It provides a simple means for controlling reversingloops or simple double track layouts. Any number of Twins can be ganged together withoutadditional wiring by using the little double-ended connectors provided. Black plastic Twin has 2 red switchesuseful for reversing section and turntable control on single-cablayouts, sidings, wyes and so on. Instructions are listed on the back of the package. INCLUDES: One Twin Electrical Control