Some bento boxes that I have seen are long and flat like tv dinners, but I find they do not fit nicely into a kids’ size backpack. My bento box has 2 small square containers, 1 large rectangular container that both fit into the mold with the freezing gel. The box also has a lot of space underneath to pack sandwiches and other goodies when the bottom extends. This versatile lunch box fits snugly in an insulated lunch bag and is perfect for a smaller knapsack. I also have space for a small water bottle in the lunch bag if I choose. I am so glad I switched to the bento box for lunches, I am thinking of getting one for myself!