The BLACK + DECKER TLD100 Thermal Leak Detector will help to identify both hot and cold draughts around your home. It has a large LED display that shows the temperature in either Fahrenheit or Celsius. The detector automatically switches between shining a blue light for cooler leaks, or a red one for hotter targets. Powered by a single 9V alkaline battery that sits neatly into the handle where the switch is located. Allows you to make your home more comfortable and energy efficient. Ideal for those concerned about the effects of global warming. Power: Alkaline 9 V (Not supplied).