It sounds like you want a mirror to attach to your bike, but I dearly love my helmet mirror. After riding a while, I find myself looking for it when I'm NOT riding and hear something behind me!!! Here are photos:
View from in front of the helmet. The black visor makes it harder to see the mirror and how it attaches, but it attaches to the helmet with zip ties. Very handy when it comes time for a new helmet! Just snip and re-zip on with new zip ties.
And, here's a view from behind the helmet.
In these photos, you can also see how the mirror is durable and endlessly adjustable because the "pole" that is between the mirror and the helmet is made up of 8 ball-and-cup joint things. If over-rotated and it pops out (which has happened to me once), it's easy to pop back into the socket. Very different from the previous very delicate and easy to break helmet mirror which I purchased (and returned) due to it's delicacy.
For anyone interested, this mirror is made by the company "Efficient Velo Tools" (IMO, a perfect name for this company!) https://www.efficientvelo.com. I have no connection with this company except as a happy purchaser of their awesome helmet mirror.
I second the take a look mirror. I have it attached to my helmet and I will never go back to an attached mirror to my handlebars. with a helmet mirror you can do a full scan behind you with just a small movement of your head. it allows you to see both the left and right side rear views.
Pictures of Venzo mirror mounted on bike. I decided to mount the mirror on top of the handle bars instead of underneath it works perfectly just need to glance to the side instead of looking down. Took a short ride and mirror does the job. No distortion objects are very clear and appear at the distance that they are at.
I have the Mirrcycle on my human powered commuter bike. It works ok (I'd give it a 6 on a scale of 1-10). It matches that bike better than some others because it is set up as a city commuter. But when I bought my ebike, Chris at Propel set me up with a Busch and Muller ebike mirror. I think it is this one (image below). It is much better than the Mirrcycle I have. It folds up easier and has a larger field of view. I think Busch and Muller has some other options as well.