... : 1,Suppy heat 20 hours 2.Automatic heating 3.Supply hot & cold packs 4.No non-toxic Supply good quality ... :1) It can provide hot more than 20 hours.2) Ave. Temperature: 52 centigrade3) Material: Iron powder, water, cellulose, salt etc...4 ... , hunting, fishing, skiing and skating; For use whenever and wherever hot therapy is needed, such as Myalgia, lumbago, internal injury caused ...