SAVE MONEY: Homeowners save up to 23% annually on heating or cooling costs, plus ecobee pays for itself in under 2 years (compared to a hold of 72 degrees). WORKS WITH ROOM SENSORS: Place them in the rooms that matter the most and have the temperature balanced throughout your whole home. Measuring both occupancy and temperature, sensors signal your ecobee Smart Thermostat to automatically switch to the right mode for comfort when you're home or for savings when you're not. 2pk sold separately. EASILY INSTALL YOURSELF: It only takes about 30 minutes, thanks to an easy to follow installation guide and an in-app step-by-step walkthrough. Everything you need comes in the box, including a Power Extender Kit for homes with no common wire (C-wire). CONTROL FROM ANYWHERE: Easily adjust your thermostat from wherever you are using your iOS (iPhone, iPad, Apple Watch) or Android device. The ecobee mobile app is available in the App Store or on Google Play. PLAYS WELL WITH OTHERS: ecobee3 lite works with your favorite smart home setups, including Apple HomeKit, Amazon Alexa, Google Assistant, Microsoft Cortana, Samsung SmartThings, Wink, and IFTTT.