[Quality Material]:This USB heated lunch box bag is made of Oxford cloth with an inner lining of aluminum foil and heating components.It's waterproof and easy to clean,ensuring long term use [Easy to Use]:Lunch warmer simply place your lunch box inside,plug in the USB cable,and the bag will automatically heat up to about 50 degree before switching to preservation mode.A 5V2A plug is required.There is a small circle and a small vertical dot on the switch.The small vertical dot is on and the small circle is off [Versatile Use]:With a power rating of 9W and a voltage of 5V,this heated lunch box bag is suitable for various occasions such as home use,office lunches,camping trips or picnics [Convenient]:The food warmer heater has a handle,making it easy to carry when going out,suitable for long commutes or office lunches [Ideal Gift Choice]:This practical and stylish tote can be a nice gift for your friends or family members who need to carry meals around regularly