It is designed to keep food warm or cold for several hours, with some models claiming to keep food warm for up to 8-12 hours.
The inner tank is made of food-grade 304 stainless steel, which is durable, easy to clean, and safe for food storage.
The lunch box often features a leakproof silicone seal to prevent spills.
Some versions are designed with multiple layers or compartments to separate different foods.