it, you have to put the whole lid on the freezer.
love the concept of this! however, the fact that the ice pack is in the top, you are not able to prepare the lunch the night before. if you do, then you have to cover it with foil or something else in order to keep it from spoiling/going stale, which sort of defeats the purpose. so, i just stopped using it as my main lunch "bag".
bought these for my 3½ year old for his first year of preschool. they work great. easy to freeze the lid and does keep things cool enough until he eats at 1130. my only complaint 