Professional Thermostat and Hygrostat to control temperature, with different day / night settings. These units have a LCD control panel with memory back up battery, output block and remote temperature probe. The 2 outputs are controlled as follows:A – Temperature controlled by remote probe. Day and night setting; temperature differential setting of 1C to 15C (ie on at 29C, off at 31C upto on at 22C, off at 38C). Can be used to control heating or cooling. Also has upto 4 on/off settings over a 24hr period. Use for heaters or coolers where day temperature and night temperature are different. B – Output controlled by upto 4 on/off settings over a 24hr period. Use to switch day only lights on, or night time moonglow lights. Specification:Temperature Range: -20C to 50C Day and Night Temperature settings Accuracy: +/-1C Temperature Control Range: 0 to 50C Temperature Differential Range: 1 to 15C Timer Control: Upto 4 on/off periods every 24Hrs Controls either Heating or Cooling Memory protected by back up battery Max 600W per output