Hey y’all, new member here, and new owner of a little set of basic o rings. Used to always diving with my dad as my buddy and he carried a set so I didn’t have to. Now that I’m moved out and diving “alone” more, I picked up my own little basic set. Question is, where the heck do I use them? What O rings are you “allowed” to replace yourself? I know tank valves but that’s it really. So why buy the set, where else can I use it? Thanks y’all.