Reptiles are ectotherm, and use heat from an external source to thermoregulate their optimal body temperature. Most reptiles use direct radiant heat from the sun in combination with conductive heat from sun-heated surfaces such as branches, rocks or other heat accumulating structures. Providing such an appropriate, species related, temperature gradient in the terrarium is an important factor in successful reptile keeping. With the Exo Terra 100W Electronic ON/OFF Thermostat you can create a well-controlled heating system that allows you to maintain the required temperature conditions similar to those found in a desert or tropical environment. The Thermostat will also help to prevent overheating and undercooling during hot summer days or cold winter nights. The electronic Triac switch keeps the temperature at the desired setpoint with a much higher accuracy compared to conventional thermostats and virtually eliminates temperature swings in the terrarium. Simply connect your Heat Mat, Heat Cable or Ceramic Heater to the Exo Terra ON/OFF Thermostat, set the preferred temperature and place the heat sensor in the desired spot. The Red LED heat indicator will light up when the heating device is ON and will shut off once the desired temperature has been reached. The recessed dial of the thermostat will prevent accidental temperature change if the device is being handled. The Thermostat comes with a 3.6 foot / 110cm power-cord with grounded plug & receptacle for increased safety and to allow the use of a power outlet strip. The waterproof remote sensor can be safely used in highly moist terrariums and aquatic environments. The Exo Terra® Thermostat should be set according to the needs of the animals. Thoroughly research the preferred optimum temperature range (POTR) for your specific reptile, so you can create the correct temperature gradients inside the terrarium to allow your reptiles to thermoregulate.