Equipped with high precision sensors, the STC-3028 is a compact thermostat with accurate and stable performance, widely applied to many fields. It is easy to operate. The heating and cooling can switch automatically, and the temperature is controlled by difference set value. Designed with ABS flame-retardant casing, it is safer and reliable to use. Specifications: Model: STC-3028 Material: ABS Color: Black Supply Voltage: DC 12V / DC 24V / AC 110~220V (Optional) Power Supply Frequency: 50/60Hz Output Control: Relay Output Output Power: Max. 10A Temperature Measurement Range: -40~+110 Humidity Measurement Range: 0%~100%RH Temperature Accuracy: plusmn;0.3 Humidity Accuracy: plusmn;3% Item Size: Approx. 8.5*7.3*3.4cm / 3.35*2.87*1.34in Item Weight: Approx. 91g / 3.21oz Package Size: Approx. 10.2*8.3*6.2cm / 4.02*3.27*2.44in Package Weight: Approx. 160g / 5.64oz Note: Please read the User Manual carefully before use. Strictly distinguish interfaces of relay, sensor and power. Strictly distinguish connection of sensor and power. Sensor down-lead and power wire should be kept a proper distance. Packing List: 1 * Temperature Controller 1 * Temperature Sensor 1 * User Manual (English)