Built-in fixed thermostatic control automatically maintains the temperature between 18C-23C. Includes A guide to successful propagation. Long life economical heaters. 22 watt heater. Premium quality range. Humidity and air. Temperature control. Crystal clear cover. Durable base tray. Sealed heating unit. Supplied with a starter kit. This propogator has a thermostatic control that automatically maintains a temperature between 18c -23c by the base heating up when the temperature detected is below this range and turning off when the temperature detected is within this range, this not variable or able to be adjusted by the user.Will my propogator base be warm to touch?No, it will not as the human body temperature is high than the temperature of the base so it will always feel cool to touch however do not panic it will still be doing it\'s job and maintaining the temperature range of 18-23c - a soil thermometer will help to confirm this.