Google Nest Nest Temperature Sensor

"Meet the Nest Temperature Sensor. Most homes aren’t the same temperature in every room. With the Nest Temperature Sensor, you can let your Nest thermostat know which room should be a certain temperature at a certain time of day. Just place it on a wall or shelf and get the right temperature, right where you want it."

Features:

• Helps make sure a certain room is the exact temperature you want it to be.
• Put temperature sensors in different rooms. And choose which room to prioritize when.
• Place it on a wall or shelf. Then forget it’s even there.