The Heat Jacket from Harkila is for those days when temperatures are extremely low. It is lightweight with a heat reflecting lining that helps prevent heat loss. It has heating membranes sewn into the back and lumbar region of the jacket that can be activated from a smartphone app or by using the push button on the chest. The smartphone app can be used to set the temperature anywhere between 30C and 52C. The push-button on the chest activates the heating membranes to temperatures 38C, 46C, or 52C. Once the jacket is at the desired temperature the membranes will automatically turn off. If the temperature drops 2 degrees below the desired level they will turn back on. The heating membranes are small, flexible, and will not restrict movement whilst wearing the jacket, and can be folded away easily into the dry jacket supplied. The jacket also features a USB port that can take can be connected to a power bank of your choice. An excellent highly technical jacket that will not disappoint. Heat Jacket FeaturesHarkila lightweight jacket Heat reflecting lining that prevents heat loss Soft fleece-lined collar Heating membranes are sewn in the back and lumbar region of the jacket and can be activated from a smartphone appTemperature can be set between 30C and 52C on the smartphone appMembranes can also be set to 38C, 46C, or 52C by pressing the push button on the chest The membranes do not restrict the movement of the jacket Folds easily into supplied drybagUSB plug-in right hand pocket *power bank sold separately* Output temperature of 52C has a duration of about 7 hours when the outdoor temperature is 0CWhen the jacket reaches the set temperature the membrane will automatically go into standby The membranes will automatically turn back on if the temperature drops 1-2 degrees below to set levelMachine washable Harkila\'s Ref.MPN: 10011862507Colour: Willow Green/BlackSizes: Small, Medium, Large, XL, XXLPM Ref. 1405769