Honeywell Boiler Control Panel, 4 Zone, Dip Switches, Used with AQ1000 2 Wire Thermostats, 30 Second Boiler Heat Post Purge, 24 Vac R-C Input, Low Voltage B-B Communication Bus Terminals, Low Voltage Zone Module Thermostat Input, 120-240 Vac ZR-ZC Contact Rating, Wire Clamp Screw Terminals, Expandable to 16 Zones