The inner layer of the bento lunch box is made of high-quality stainless steel, mirror-polished, and easy to clean. The lunch box is designed with a silicone sealing ring, which improves the sealing performance of the lunch box, has long-lasting heat preservation and is convenient to open the lid. The outer layer is made of food grade PP material, high temperature resistant, safe and hygienic. The hot food insulation lunch box can be kept warm at 77 degrees Fahrenheit for about 1 hour, and the heat preservation time will be longer when matched with an insulation bag. The hollow design has almost no heat preservation effect in the cold winter. The duration of heat preservation is related to the local weather of the day. The bento box is not only suitable for going out, but also for ordinary tableware at home. The insulated lunch box uses a stylish short buckle design. There are safety latches on both sides of the lunch box. The short buckle insulated tableware can be easily fixed with one button. Don't worry about the lunch box loosening. The hot food thermoss has a portable concealed double-curved handle, which is suitable for home, work, travel and school. The thermal insulation lunch box is exquisite and generous, and does not take up space. We take buffering and shock absorption measures on the packaging to ensure the integrity of the lunch box transportation. If there is any damage or other problems, please contact our email for a solution, thank you for your understanding. The insulated lunch box will bring you a happy, healthy and satisfying dining experience. Children's adult bento box adopts vent design and pressure cooker principle. Press and hold the vent to seal. When opening the lid, first open the upper ventilation hole, and then open the lid. The lunch warmer has good airtightness and can be removed for cleaning without leaving stains. The hot lunch container is connected by plastic, which is not easy to fall off.