NTC temperature sensor allows the module to intelligently control varied electrical devices based on the temperature. NTC thermistor has a negative temperature coefficient, which means the resistance decreases with increasing temperature. The relay can operate at voltages up to a maximum of 240V AC at 5A or 14V DC at 10A to power on. The temperature is displayed in degree centigrade and with the help of 7-segment display and the relay, the state is displayed with the help of the LED present on the W1209 module. Indicator: off indicates the relay is switched off; always indicates the relay is closed. LED: shows ll means the sensor opens; shows hh means it s out of range, the thermostat will be forced to close the relay, the display as high temperature protection. Temperature range: 50~110 and deg; c resolution: 0. 1 And deg; c(9. 9~99. 9 And deg; c), 1 and deg; c(other ranges) accuracy: 0. 1 And deg; c refresh rate: 0. 5S high temperature protection: 0~110 and deg; c input power: DC 12v static current: and le; 35ma, attract current: and le; 65ma measurement input: ntc(10k 0. 5 Percent) waterproof type sensor output range: 1 channel 10a relay output environment: 10~60 and deg; c? Humidity: 20 percent 85 percent model: wh w1209 size: approx. 48X40x15mm specification: how to use: connect the power supply and the load, then you can supply to the controller. It displays the measured temperature, press set key, the display temperature flashing, press plus to set the desired temperature. After finished, press set to confirm and back. Now the controller automatically performs the relay by setting off. This temperature controller output is 10a relay, meeting various high power loads, please make sure the wires are connected correctly. Package includes: 1x digital temperature control.