They are typically made of food-grade stainless steel, which is durable, non-toxic, and easy to clean.
Vacuum insulation technology helps maintain food temperature, keeping items hot for up to 9-12 hours or cold for up to 14-24 hours.
Some models, like those shown in the bottom left of the image, include multiple food trays with seal covers to separate different food items and prevent spills.
They often come with accessories such as a lid that can double as a cup and a folding spoon.
Various capacities and colors are available to suit different needs, from small individual portions to larger family sizes.