The T5+ Smart Therostat comes with an optional power adapter. Wi-Fi thermostats typically require extra power via a "C" wire. Many homes lack this wire, so this adapter gives you a simple, low-voltage alternative. It's easy to install and fits discreetly near your heating and cooling system. The T5+ Smart Thermostat provides 7-Day flexible scheduling or location based temperature control. Geofence technology helps make you comfortable by using your smartphone's location to know when you're away and when you return. 1) Smart Alerts - Push notifications remind you to change your filter and warn you of extreme indoor temperatures. 2) Auto Change From Heat to Cool - Automatically determines if your home needs heating or cooling to provide maximum comfort. 3) Fan Operation - Custom fan settings to circulate more or less air, as needed, to keep air moving throughout your home. Fan control dependent on wiring configuation. 4) Display Options - C or F temperature display, 12 or 24 hour clock configuation, touchscreen display, displays set point and indoor temperature simultaneously, +/- 1 F degree temperature control, permanent and temporary temperature hold, 5) Smart Response - Leans your home's heating and cooling cycle times to deliver the optimal temperature at the right time 6) Works with Apple HomeKit, Google Assistant, and Alexa.