The Thermos Freeze Board is an effective way to keep food and drinks cool on a day out. Freeze it in the freezer, and when you're ready to go, simply place it at the bottom of your cool bag or picnic hamper to avoid warm, soggy sandwiches. It's a great alternative to traditional freezer ice packs. The freeze board is made from tough polypropylene with a heat-sealed, leak-proof cap and contains a non-toxic aqueous liquid. Its flat design makes it ideal for placing at the bottom of cool boxes and picnic bags.