Features:* 1. It is made of waterproof oxford fabric that is not afraid of rain. And the aluminum foil lining makes it easy to clean, stains can be wiped off easily.*2. With the USB port, heating is more convenient. Durable and long-lasting zipper runs smoothly and fits tightly, not easy to get stuck.*3. Two heating modes, powered by a power bank or phone charger, which is more convenient to use.* 4. There is a side bag to store the power bank, it makes it easy to carry outdoors.*5. Can be customized according to the heating demand of sandwich boxes and various foods, and provide hot food. Description:* 1. Material: Oxford Fabric* 2. Color: Black, Grey* 3. Size: 21*16*8cm* 4. Weight: About 200g*5. Heat retention function: heating up to about 50°C, it will automatically turn into a heat retention statePackage Contents:Bento cooler bag*1USB cable*1 (without Power Bank)Note:1. All photos are professionally color-coded, but due to the difference in ambient light and display device settings, there may be some deviation between the displayed photos and the items themselves. Please understand.2. The data is measured manually and there may be some variance, but this will not affect usage.