The HC1D Oxygen Fuel Cells are the power source for HydraCell Aqua Tac and Aqua Flash torch. HC1D HydraCells can be stored sealed, prior to first use, for 25+ years. They are activated to full capacity by simply dipping in water for 15 seconds. Once activated the cells will operate continuously under load, requiring only periodic re-hydration. At the end of the useful lifetime of the cells, they can be easily replaced.