Here are some pictures of the Producer Talkback box I built for sports radio broadcasts.
It allows the Producer to talk to any or all of 6 people by pushing the appropriate button.
1. The interior connections. 1 XLR and 1 1/4″ for headset connection. 2 RJ-45s to move audio to and from the mixer.
2. The underside of the lid, with the terminal strip, DPDT switches, and volume pot visible.
3. Just before I finish the mic connections and close the lid.
4. The top of the complete box with 6 DPDT buttons and volume knob.
5. Left side of the box for headset connections.
6. Right side of the box with 2 RJ-45 connections for ins and outs.