Ideal for use in cool bags, cool boxes and lunch boxes, Thermos Ice Packs help to keep food and drink cool and fresh for hours. Simply freeze them overnight and they are ready to go. Features and Benefits Tough - Made from strong polypropylene, the packs are completely leak-proof. Easy cooling - Just freeze overnight for hours of next day cooling. Dry - Do not produce any watery residue. Specifications Material: Polypropylene Heat-sealed leak-proof cap Non-toxic aqueous liquid Dimensions (per pack): H18 x W9 x D3cm  2 x 400g