This is XH-W1209 12V Digital Temperature Controller Module W/ Display and NTC Waterproof Temperature Sensor. W1209 Mini thermostat Temperature controller is low-cost 12V Temperature controller with 7-segment display and 3 switch keypad for setting temperature and other parameters. The module features an NTC thermistor temperature sensing and has an accuracy of 0.1 C. The XH-W1209 12V Digital Temperature Controller Module W/ Display and NTC Waterproof Temperature Sensor is an incredibly low cost yet highly functional thermostat controller. With this module, you can intelligently control power to most types of electrical device based on the temperature sensed by the included high accuracy NTC temperature sensor. Although this module has an embedded micro-controller no programming knowledge is required. 3 tactile switches allow for configuring various parameters including on & off trigger temperatures. The on-board relay can switch up to a maximum of 240V AC at 5A or 14V DC at 10A.  The current temperature is displayed in degrees Centigrade via its 3 digit seven segment display and the current relay state by an on-board LED. Technical Specifications: Capacity: 10A Input Power (DC): 12V Control Accuracy: 0.1 C Refresh Rate: 0.5 Seconds Output: 1 Channel Relay Output, Waterproof Sensor: 0.5M Resolution at -9.9 to 99.9: 0.1 C Temperature Control Range: -50 ~ 110 C Measurement Accuracy: 0.1 C Measuring Inputs: NTC (10K 0.5%) Resolution at all other temperatures: 1 C Package Includes: 1 Piece-W1209 Digital Temperature Controller Thermostat Module   Power Consumption:- Static Current: <=35mA Current: <=65mA Environmental Requirements:- Temperature: -10 ~ 60 C Humidity: 20-85% Settings Chart:- Long press the “SET” button to activate the menu. Code Description Range Default Value P0 Heat C/H C P1 Backlash Set 0.1-15 2 P2 Upper Limit 110 110 P3 Lower Limit -50 -50 P4 Correction -7.0 ~ 7.0 0 P5 Delay Start Time 0-10 mins 0 P6 High-Temperature Alarm 0-110 OFF Long pressing - will reset all values to their default Working:- Current temperature will be displayed on the module in degree Celsius by default. When switched to a different mode, inactivity for approximately 5 seconds would lead to restoring the value of the module to the default temperature display. Setting Modes:- Trigger Temperature:Press “SET” button on the module and current temperature will be displayed on the screen. Using “ ” and “-“ button, one can set the temperature in 0.1 degrees (Celsius) increments. No activity for 2 seconds will result in setting and storing the trigger temperature and then the screen will display the current temperature. Parameters Setting:- Pressing the “SET” button for a minimum of 5 seconds will lead to the setting of the parameter present in the module. The seven segment display will start with the display of first parameter “P0”. Pressing ‘ ’ or ‘ – ‘ buttons will help to go to parameters (P0-P6). Pressing “SET” button midst the parameters will let you change the value for that parameter. After setting the required parameter, press set button to exit that option. If no button is pressed for 5 seconds the thermostat will exit the parameter option and will return back to the default temperature. Heating Parameter P0: P0 has two settings, C and H. The default setting C can be used to connect to an air-conditioner as the relay energizes when the temperature is reached. Setting H leads to de-energizing the relay when the required temperature is detected. It can be used to control any heating device. Hysteresis Parameter P1: This parameter sets the range of change in temperature that must occur before relay will change state. Parameter P2 (Upper Limit Temperature): P2 limits the maximum trigger temperature that can be set. It acts as a safety feature that stops the user to set an extremely high trigger temperature. Parameter P3 (Lower Limit Temperature): P3 limits the minimum trigger temperature that can be set. It also acts as a safety feature that stops the user to set a low triggering temperature. Offset Correction Parameter P4: Changes can be made if there is a difference between the displayed temperature and actual temperature reading with this parameter. Delay Parameter P5: Delay in the switching of the relay when the trigger temperature has reached, can be set by the help of delay parameter P5. It can be set in one-minute increments up to a maximum of 10 minutes. Alarm Parameter P6: This parameter causes the relay to switch off when the temperature reaches its settings. The display will show ‘ — ‘ to indicate an alarm condition. The relay will not re-energize until the temperature falls below this value.