What is my seal called?

Wow that kids was right. Thanks for checking for me. I just watched a video on you tube..."different vehicle", and he was using white out to line everything up and counting threads. I am gonna find out the torque and do it right.
I just need to make sure there is nothing else that needs replaced.
My car sat for 20 years. There only 69k on it. SO the seal must have dried out.

ahh beat me to it lol. I type really slow. Good luck. The white out method works good too for marks. I just would be afraid of whiping it off and losing my marks. IMO