Pool Tool Company Inline Anti-Elect Zinc Anode, 2in. Plumbing 104C-2

This anode is already working, I can tell by the corrosion already present after just a month. Best mounted upright so that the air pocket goes up and can be cleared with the valve in the top. I mounted sideways and have an air bubble that persists. Doesn't seem to effect how it works. I think it's a good solution if you want to feel better about the chances of the expensive heater you just bought not getting corroded.