1.Temperature control: with this sleeping bag you can regulate the heat via a USB plug. If the outside temperature allows the power bank to function properly, the heating function of the sleeping bag can be used. Suitable for temperatures from 10°C to 20°C. 2. and soft material: the fabric is made of polyester fibre, while the filling material is made of down cotton. The waterproof and moistureresistant properties ensure that you stay dry during outdoor camping trips. Plus, it's incredibly soft and provides comfort and protection from moisture. 3.MULTIFUNCTIONAL DESIGN: When the zipper is fully opened, the thermal sleeping bag transforms into a down comforter or quilt. The bottom and side zips of the sleeping bag can be opened independently, so you can adjust the temperature according to your wishes. There is also an internal storage bag to store your phone, wallet or keys. 4.COMFORTABLE SLEEPING EXPERIENCE The skinfriendly and soft material ensures a comfortable sleeping experience even in harsh and cold environments. Compared to conventional sleeping bags, our sleeping bag better breathability, dryness and warmth, so you can enjoy a cosy and restful night's sleep.