** Note - People have indicated my replies don't seem to be making it through. Please provide a # for texting if you can when contacting me. Thanks. ** Thermostat was used for 4 months before our heating system was replaced, and came with its own thermostat. Model is an older RTH7400D Check the second image to ensure compatibility with your heating system, please. Features a 5-1-1 day schedule, many hold options, etc. Open to offers. Thanks for looking.