I assume you are talking to me.
It is the only anode on my heater. The old one is 15 years old. I got the anode form this web site. It is magnesium.
I have cleaned out and replaced elements in water heaters before but this is the first time I have taken one all the way down and cleaned out and replaced the elements, anode and dip tube. The only thing that is original on the tank are the thermostats and one element.
I was very surprised it was so easy. It was just time consuming. Of course, mine is electric. But I can’t see how replacing the anode and dip tube in a gas heater would be that much different. If you don’t know how to sweat a copper joint then a plumber is in order.