That is your anode it looks good & you should get another year or two out of it. When it looks very thin time to replace. It protects your water tank.
From Google .... What is an anode rod? The short and simple answer is “Sacrificial rod used mainly in water heaters. It helps protect the lining of and generally lengthens the life of a water heater.
Most of us only empty the hot water tank once a year when winterizing. In 30 years of camping have yet to have a water tank go bad.