Specification: The gas boiler thermostat ME83B is with digital LCD display. It is powered by 1.5V two section AA batteries. It is used to control heating boilers to start or stop work to adjust the temperature. Thermostat detects room temperature, when the actual room temperature is below your set temperature, thermostat regulates the boiler to start working. Then the thermostat controls the boiler to stop when the actual room temperature is higher than your set temperature. Characteristic: 1) Convenient to mount on the wall or stand anywhere. 2) Wireless, AA battery powered, can put anywhere you want. 3) Can set 5+2 weekly programmable. 4) Child lock to avoid misoperation. 5) Antifreeze function. Details: 1. Working voltage: 2 x 1.5V AA battery (not included) 2. Power Consumption:? 150uW 3. Temperature control range: 5~99?, (factory setting is 5~35?) 4. Temperature limit range: 5 ~ 99? 5. Temperature control accuracy: ± 1? 6. Size: 85x85x28mm 7. Sensor: built-in 8. Color: white 9. Backlight: blue or white Attention: Water heating thermostat no outdoor sensor. Package list: 1 x thermostat 2 * Screw 1 * Instruction Manual