A vest with a built-in carbon fiber heating element with nine heating zones in the back, neck, and abdomen area. It operates from an external battery (not included in the set) and will provide a feeling of warmth and comfort in any weather. Heating is provided by a special high-tech film made of carbon nanotubes located under the lining of the product. For maximum comfort, you can manually select one of three operating modes or use the automatic one: after 5 minutes of operation at the maximum heating level, the heater will automatically switch to medium intensity mode. When using a 10000 mAh battery, the heating element will work for 6 to 12 hours depending on the selected operating mode and ambient temperature. The vest has a zippered closure with a stand-up collar and 2 outer pockets. An inner zippered pocket for the battery. 9 heating zones: 6 on the back, 2 on the abdomen, and 1 on the collar. 3 heating modes: up to 45 (highlighted), up to 35 (highlighted), up to 25 (highlighted). Required power supply: 5V, 2.1A. Maximum power: 7.5W; current: 1.5A; voltage: 5V. It is recommended to use an external battery of at least 5000 mAh (it has an additional inner zippered pocket). Before washing, cover with the included silicone cap and remove the cord in the pocket. Do not turn on the heating if the vest is wet. Comes in an individual package with Heating Activation: 1. Connect the external battery to the cable in the inner pocket of the jacket. 2. Press and hold the heating button for 2-5 seconds until the color indicator lights up. 3. Press the button again to select the temperature mode. 4. To turn off the heating function, press and hold the button for 2-5 seconds. Size chart, cm 3XL 4XL 56 58 60 62 64 66 68 70 72 74 76 78 79 80 Deviations of up to 5% from the specified parameters in size and color are allowed.