I've researched it & it's phosphoric acid,at a highly inflated price. The chemistry is logical. Food grade phosphoric is around $20/ litre. Without looking at my records I think 20ml / cell in z70 size battery is all that is required. ( follow the inox directions as to how much per cell) I've witnessed it clean up dirty looking acid in battery cells. As to adding to longevity it a bit hard to tell from my last pair of new batteries as some low life stole them, and a heap of other gear ! If your using flooded cells it's well worth a try & if you get a litre of phosphoric acid you have plenty of great metal cleaner left over