These are additional replacement electrodes that are already included in each of The SilverLungs Generator kits. These (.9999|99.99%) pure silver electrodes will easily last for 4,000+ batches of full strength 20 PPM silver. These electrodes come pre-cut, polished, straightened and ready to use.
These giant silver electrodes were designed to last almost indefinitely as to never be replaced. We have confirmed more than 4,000+ batches (1,000 gallons) on the same set of silver electrodes with plenty of silver remaining. It is not required to purchase a backup set!