Follow up. After 14 years, the anode was 90% gone,and the folding replacement went in easily. Advice: don’t even think the hex head anode can be removed without a sturdy impact wrench and a 6 point 1 1/16 impact-rated socket. Locate a rental facility before you buy the new anode, there was only one electric 1/2 impact wrench in the whole Boston area. A DeWalt DW292 did the job with just a few attempts.