The service manual has plenty of information including configurations, installations, faq's and a full list of parts.  To open the manual, click on the following link:

Sales Documentation:
  • Audio/Video Communication Systems
  • Audio console
  • Audio console accessories
  • Video accessories
  • G5501-1 Kit
  • Greyfield Video Units
  • Greyfield "In Wall" Unit (G5572 & G5573)
  • Greyfield "In Wall" Unit with camera (G5574 & G5575)
  • Greyfield Remote Customer Audio Units
  • Plantronics Headset Installation