It comes in a light, flat sheet that expands into a 24-cell ice pack by just adding water. When used as recommended, Techni Ice stays frozen for days - 6 times longer than ice and 3 times longer than gel packs and most other ice packs when used in the same volumes. Techniice is a food grade product which remains flexible when frozen, can be cut to size and is completely safe and non-toxic. Techni Ice is reusable for years because it has a unique 4 layer/ply construction. This consists of two heavy duty, washable plastic surfaces on both sides, plus a two layer textile sheath on the inside to contain the polymer and resist puncture. This ensures long reusable life and provides insulation for superior performance. Besides a cold pack Techni Ice also doubles as a Heat Pack. The same sheet of techniice can be used as both a hot pack and cool pack.