Features: Heat relief for up to 3 days, Worn around neck or forehead, Infinetly re-useable, Non-toxic, Doubles as a hot pack if required. A simple but highly effective body cooling product which works by evaporation. Immersion in clean water for approximately 15-25 mins allows poly-crystals to absorb and retain a large volume of water. When worn, the retained water evaporates and draws away body heat creating a cooling effect. Cooling effective increased by refridgeration. Great in hot conditions. This was previously known as a 'Cobber'. Although that brand is now discontinued this is the same item. This item is commercially made and brand new.