Google Nest Thermostat. The nest thermostat works with most 24V systems, including gas, electric, oil, forced air, variable speed, heat pump, and radiant. It can control one stage of heating and cooling and a second stage of either heating or cooling; heat pumps with auxiliary or emergency heat and fans, one speed. The connector can accept only one of these wires: Y2, W2, or O/B. The nest thermostat is designed to work in most homes without a common C Wire. Some systems including heating only, cooling only, zone controlled and heat pump systems, require a C wire or other compatible power accessory.

Whats all included:

Nest Thermostat, 2 1.5v AAA batteries, base plate, and wall screws.