KB701 Single-Channel Flush-Mount PTT Speaker Station

KB-701 1-Channel Flush-Mount Push-to-Talk Speaker/Mic Station Mounts
in the V-Box or Accessory Enclosure (8.25" X 4.5")

The KB-701 remote speaker station connects to a single channel of
party-line intercom and operates in half-duplex mode. It features both
an integral speaker and a flush mount ...