The EVT Safe Zone mirror is in a class of it's own. By leaps and bounds it is bigger, tougher, and more stable than anything in existence. American made, best customer support possible, 5 year no-fault warranty. It was obviously invented by someone who only cares about how well it functions. It's got an enormous flat reflector so you can see finer details. You can actually tell if someone's texting at the wheel. It's pretty much indestructible too. You can even pick up the helmet by the mirror! The cost reflects how much better it is than anything else, but you don't have to replace it every year so in the long run it's actually cheaper. You gotta try one.
https://www.efficientvelo.com/home/safezone/