There's been some questions regarding problems fitting the -
Hafny Bar End Bike Mirror - Into the tubes of the handlebars of the Radrover.

I'm happy to report that I just easily and successfully installed the -
Hafny Bar End Bike Mirror, HD, Blast-Resistant, (62mm) Glass Mirror, HF- MR090B -
In the left handlebar of my newly acquired 2020 Radrover Step-Thru 1.

I gently pried the left handlebar end cap off of the grip with a very small screwdriver tip.
The inside diameter of the handlebar is an unobstructed smooth tube - Approximately 18mm in diameter.
This mirror mounting tube bracket is supposed to fit -
Inside handlebars with 14.8mm ~ 23mm inside diameters.

The mirror's mounting shaft - With the included circular shim on the shaft - Fit snug - But perfectly.
A couple of gentle turns with a 5mm hex wrench to expand/tighten it slightly - Done.

There are multiple choices of - The types of glass (silver/blue) - And sizes (62mm/68mm) - Of this mirror.
There is also a stainless steel mirror version, as well.
But the mounting insert tube bracket on all of them is the same.

Disclaimers: I paid for the mirror (Amazon) and received no compensation for this posting.