The RCM-S is a SPDT center-off switch used for switching program busses in conjunction with an RCM42B or RCM-82B Room Combining Matrix. The standard RCM-S comes labeled as Group A, Group B and Local, but custom labeling is available. The module mounts into a standard single-gang electrical box (not provided), and is finished off using a matching decora coverplate. Connections on the sound system side of the switch are made via pigtail wires. Modules are available in Brown, Ivory or White.