You can use Flair Smart Vents with any thermostat. There are a few differences if you're using Flair with a Smart Thermostat or with a regular thermostat.
If you're using a regular thermostat, Flair will help balance temperatures throughout your home by automatically adjusting your Smart Vents based on temperature. A Flair Puck installed in a room will be able to control whether a Smart Vent can open and close in that room. However, in this situation the Flair Puck will not be able to turn your home heating or cooling on or off. Learn how to set up Flair with a regular thermostat here.
If you have a Smart Thermostat, like a Nest, ecobee, or Honeywell Lyric, you'll be able to access Flair's full feature set. Learn how to set up Flair with a Smart Thermostat here.
If you have a Mini Split, Window AC, or portable, the Flair Puck is your Smart Thermostat! Flair does not replace your Smart Thermostat. Think of Flair as an extension of your Smart Thermostat that gives you temperature control in any room of your home.