Included in side. CM921, CMS921, CMS921B1042. CM927, CMS927, CMS927B1049. CM727, CMS727, CMS727E1016. CM721, CMS721. However, the big difference is that the Pro Series Wireless Programmable Thermostat will bind directly to any existing Honeywell Wireless Relay Boxes, where the T3 Series won't, so you don't have the hassle of having to get an installer out to fit this.
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