Double wall vacuum insulated lunch box with stainless steel inner and a small steel chutney/sauce container . Vacuum insulation technology provides temperature retention, keeping the food hot for a couple of hours. The steel inner surface is made from 304 grade stainless steel, BPA free food grade material.This lunch box is over all very durable and perfect for kids for their carry-on meals. The steel inner makes cleaning easy and keeps the food hygienic and edible for hours. Kids are going to love to carry this sleek and attractive looking lunch box.