This temperature controller is equipped with a digital screen for straight view of temperature, with four buttons for you to do easy and quick operations. It has multiple functions, programmable start and shutdown, interval working settable, constant temperature controlling mode.Features: Made of premium plastic and sensitive electronic components, which can enable you to do precise temperature control with accuracy of 0.1. It can be used to heating and refrigeration, the max range is -55-120, and the range is adjustable to meet your different uses. Equipped with digital screen, showing the environmental temperature or temperature you set. With four buttons for you to do quick and easy operation. Comes with necessary fittings, easy to install. Widely applicable to many uses, aquarium, farm, etc. Specification: Material: Plastic and electronic componentsOptions: 12V-Red; 12V-Blue; 24V-Red; 24V-BlueTemperature Measurement Range: -55-120Measurement Accuracy: 0.1Control Accuracy: 0.1Control Accuracy: 0.1Hysteresis Error: 0.1Refresh Rate: 0.2sInput Voltage: DC 12VMeasurement Input: NTC(10K0.5%%)Output: 10AWorking Temperature: -10--60Working Humidity: 20%-80%Consumption: quiescent current40MA; attracting current65MASize: Approx. 71 x 41mm / 2.8 x 1.6inchWeight: Approx. 55g Package Included: 1 x Electric Temperature Controller1 x Cable1 x Installation Fittings SetHow To Use:1. Get this temperature controller powered, the screen shows environmental temperature, press "SET" button and number starts to flash, press the buttons for setting you desired temperature.2. Long press of "SET" button to enter setting system, after setting and press "ENT" button to reture to initial interface. When it's working, long press of "SET" button can turn it off.3. If you want to use for heating, you should set it "H" mode, for refrigeration "C" mode.Code Meaning and Settings Code Meaning Choice Factory Defaults P0 Heating/Cooling H/C C P1 Hysteresis Error 0.1-30 2.0 P2 Upper Limit +120 120 P3 Lower Limit -55 -55 P4 Temperature Correction +10~-10 0 P5 Delay Start 0-10mins 0 P6 Overheating Alarm -55~120 OFF P7 Data Lock ON-OFF OFF P8 Restore Factory Defaults ON-OFF OFF P0. If you want to use for heating, you should set it "H" mode, for refrigeration "C" mode.P1. Hysteresis Error Setting: This is the upper limit for stopping work and lower limit for restart working. If you set 37-40 for heating, then the hysteresis error should be 3, it would stop working when temperature reaches 40 and restart to work when temperature lower than 37.P2-P3. Temperature Range Setting: The temperature range can be narrowed, if you set P2 to 50 and P3 to 20, then the controller only supports control of temperature between 20-50.P4. Temperature Reset: This is the function to correct the error when the real temperature is different from the shown temperature, the correction number=measurement number+different value. If the screen shows 25.6 but the real temperature is 25.8, then set P4 to 0.2, then the temperature on screen is 25.6+0.2=25.8.P5. Delay Start: This is for compressor refrigeration, if you don't need this function, just set it to "0".P6. Overheat Alarm: This function can make an alarm when the real temperature is over your setting, and it would cut off power to protect circuit. The screen would show "H", and buzzer would makes sound like "DI".P7. Data Lock: This can prevent other people change your setting. After you set any function you need, enter P7 and set it to "ON", the data can't be changed unless you enter P7 again and set it to "OFF".P8. Restore Factory Defaults: When the setting is error or any misfunction occurs, enter P8 and turn it to "ON", the controller would restore the factory defaults.