The Härkila thermal vest is made of a lightweight fabric and lined with elastic membranes on the sides. Inside, it has a heat-reflective lining that not only prevents heat loss but also enhances the effect of the vest's heating membranes. The high collar is lined with soft fleece. In the parts of the upper body that are most vulnerable to cold, between the back and the lumbar region, heating membranes are sewn. Using the associated smartphone app, these heating membranes can be set to your desired temperature between 30°C and 52°C. The membranes can also be set to 38C, 46C, or 52C using the button on the chest, so you don't depend on your smartphone. Unlike older heating technologies on the market, Härkila's heated vest heating membranes are flexible enough to fold and store with the garment they are sewn into. The vest is also safe to machine wash. In the right pocket of the vest there is a waterproof USB socket, so you can connect a power bank of your choice. With a 10,000 mAh power bank, the vest can generate its highest temperature of 52°C for about 7 hours at an outdoor temperature of 0°C. Once the vest has reached the set temperature, the thermal membranes automatically enter in standby mode to save power. Then they automatically turn back on if the temperature drops 1-2 degrees below the level set for the vest. The result is that the jacket regulates heat, because the heating membranes automatically turn off if you get hot from exertion and turn on again when you are sitting or standing. The vest has an inside pocket, two side pockets and a radio pocket on the left chest, and is supplied with a dry bag for storage.
