What is the name of the cloth bag that Beijingers carry with them to work?

The cloth bag that Beijingers carry with them to work is usually called "lunch bag". Lunch bag is a traditional eating habit and a common tableware for office workers in Beijing. It is usually made of cloth, and it is designed with heat preservation and heat insulation, so it is convenient to carry lunch food and keep the temperature of the food. When the lunch bag is used, food can be put into the bag and then sealed with a rope or zipper, which is convenient for carrying and eating. So a cloth bag can also be called a lunch bag.