Freezable Grocery BagsThis fully freezable Lunch Box is the first and only lunchbox with PackIt's groundbreaking built in cooling. Freezable non toxic gel is built permanently into the walls of each bag, to keep food and drinks chilled for hours. It totally eliminates the need for separate blue ice packs or gel packs! Simple to use: empty, collapse and freeze the entire lunchbox overnight (12 hours). By morning, the walls of the bag will be completely frozen and ready to