STZW402 series electronic thermostat. Compatible with Z-wave controller required. Z-wave plus certified, works with thousands of other Z-wave devices. Molded plastic finish. 2 wire connection to heater. Simple programming. Display outdoor temperature. Not compatible with forced air units. Frost free warning. Display in either Celsius or Fahrenheit. Backlit screen with adjustable intensity. Activate several other functions. Ambient temperature control of ± 0.1°C. Temperature range from 5 to 30°C.