HONEYWELL AQ2558P2X Aquatrol Zoning Panel for 8 Zone Pumps. Zone expansion panel works with AQ1000 communicating thermostat to add up to 4 zones with pumps or valves to AQ2000 Series Boiler Control Panels.
• R-C transformer and B-B data bus terminal for easy expansion
• Status LCDs for easy diagnostics
• Use with 2-wire “polarity insensitive” communicating thermostats
• Replacement Parts: AQ1554P2 4-zone pump expansion module.