Material Keweis lunch box set is made of foodgrade safe PP plastic external and durable 304 stainless steel internal No rust no odor retention so you can use it without any worries Unique design fresh and elegant style perfect for aldultswomen and men KEEP FOOD WARM The stainless steel bottom of the inner layer of the thermal lunch box is designed with PU foam filling which keeps the heat preservation longer and can provide 34 hours of heat preservation effect Before use it is recommended to wet the inside and outside of the bento box with hot water to preheat After the food is cooked it is recommended to put it into the bento lunch box immediately and then put it into the insulated bag Lunch Box Set You will get 4 Insulated bento lunch boxes two large and two small to meet your different needs SMALL 142 oz 420ml LARGE 201 oz 620 ml With an insulated lunch bag enhanced insulation it is very convenient to carry out Convenient for you to enjoy tasty homemade food at work or going out Great for store soups fried rice pasta or other hot food can also be used to store cold food such as salads fruits and more Leakproof and Convenient Design Each bento lunch box comes with a double silicone seal to lock in freshness leaks and odors There is a clamshell exhaust valve on the top of the lid the hot air can be exhausted at any time which makes it easier to open the lunch box there is a handle on the top of the lid which is convenient to carry and move and can be reset after use The lunch box with double heat insulation layer design allows you to enjoy food at any time No hot feeling in hand Stackable Design The stainless steel Insulated lunch box set adopts a Stackable design which can be freely combined and stored separately preserving the original flavor of the food and making life more pleasant and refined Two sizes for easy storage of different foods