Makes Ideal Body and Hand Warmer -- HeatWave is an energy storing and releasing system which contains a super-cooled salt solution (Naac), designed to provide warmth (approx. 130F). -- To activate, gently flex the stainless disc inside; this starts the heat of fusion, changing from liquid to a solid. Thermodynamic energy is released from 45 minutes to three hours. To reuse or recharge, simply boil in water. Full instructions. 3" x 4"; 4 ounces.
