SmartZone-2X : 2 Zone HVAC Controller KIT w/Temp Sensor; Dual climate control to replace Honeywell, EWC, Zonefirst, Zonex, Durozone & more 2 Zone HVAC zone control Supply temp sensor included for efficient staging & equipment protection Universally Compatible - Works with any system; single or multi-stage Easy to install; Simple to use; 5 year mfg. waranty SmartZone features LEDs on every terminal & digital display Economy Mode allows setback of all zones with the flip of a switch. When in eco mode, the system will only energize if zone 1 makes a call. This feature is great for vacations or if some of the zones are rarely used. Save $ by using a proprietary time and temperature algorithm perfected over decades of programming, smartzone stages up and down in the most effective and efficient manner possible. 2nd stage lockout  by setting this dip switch, smartzone will only allow 2nd stage if more than one zone is calling Stage from zone 1 thermostat  allows for a multi-stage thermostat to be connected to zone 1 and control zoning instead of smartzone (not recommended in typical circumstances) Best technical support and documents (full color install guide included with SmartZone &amp; best online documentation too)