Material: oxford cloth, aluminum foil 2. Uses: lunch, picnic storage and heat preservation bag 3. Function: heat preservation and preservation 4. Weight: about 128 grams for small size and 168 grams for large size 5. Size: small size is about 22x14x28 cm, large size is about 27x16x30 cm Features: 1. Three layers of very stable materials, long-lasting freshness 2. Use aluminum film composite polymer thermal insulation cotton material to reduce heat transfer inside and outside the bag 3. Lined with aluminum foil, heat preservation and freshness, lock in nutrition, waterproof and antifouling, easy to clean 4. Safe zipper design, smooth opening and closing, easy to carry and store at work 5. Comfortable hand-held, thickened hands