iHarmony Smart Zoning System Zone Sensor, Allow the User to Change Temperature. This Unit is for Use with S40 or S30 Smart Wi-Fi Thermostat. Number of Zones: One per Zone, Display: Digital Touchscreen, Voltage: 120Vdc, Dimensions: 3-5/16" H x 4-5/16" W x 7/8" D, Weight: 0.73 lbs