1、Stainless Steel Material: Each container is made of food grade stainless steel (inner) and PP (lid handle). BPA free, safe, non toxic, no taste or smell is retained, so you can use it over and over again. 2、Exquisite Workmanship: Vacuum insulation technology and seamless welding technology can maintain the maximum temperature no matter hot or cold. Preheating or precooling before use will result in better insulation. 3、Leak Proof Design: Our insulated hot food containers come with leak proof lids. Thanks to the excellent leak proof design, you can easily take your food or soup anywhere without risk. 4、Heat Preservation Effect: The lunch box can generally be kept warm or refrigerated for 3‑4 hours, and the heat preservation rice bag can be kept warm for 4‑6 hours, which is almost twice as long as the others. 5、Ideal for Gift: Thermal lunch box container, just wrap it with ribbons, give it to someone you love so they can enjoy home made delicacy for a healthier eating style!