Heat Pack is a small heating pad to heat transport boxes of fish during transport of fish in the winter. Also suitable for shipment of aquatic plants or shrimps. The application is very simple. Only open the Heat Pack and after about 5 minutes the pad starts to heat, which lasts approximately 40 hours. Dont need to shake !Heat Pack+ excellent for shipping live insects, tropical fish, flowers etc.+ simple and safe application+ non-toxic ingredients+ long lastingmaximum temperature: 65Caverage temperature: 50Cduration of heat: 40hoursingredients: iron power, activated carbon, belmilite, salt, waterHeat Pack Size: 13 x 9.5 cm