The first semiconductor heating and cooling backpack in the industry. Equipped with Peltier elements; Instant cooling/Instant heat for 5 seconds. 3 levels of heating and heating, easy to adjust with the dial Operating Time: -4°F (-21°C); Cooling: Approx. 5 hours; -18°C; Approx. 5.5 hours; -15°C; Approx. 6.5 hours; Heating: Approx. 10 hours; 45°C; Approx. 11 hours; Approx. 40°C; Approx. 13.5 hours; Equipped with a 20,000 mAh high capacity battery that is compatible with Type-C charging (Electrical Appliances and Materials Safety Act certification, PSE Mark certified) Abrasion resistant breathable material, ergonomic design, multi-pocket storage, ultra-large capacity design Set Includes: Peltier heating and cooling backpack x 1, dedicated battery x 1, USB-C cable x 1, instruction manual x 1