Search on the term "mirrors" in the forum search box.
Many members here have added mirrors on the mounts already provided on the reservoirs. The threads on these have the details about thread size etc.
/bob 2013 White Suzuki Burgman 650 ABS - my current ride
2003 Honda Metropolitan CHF503 - wife's ride flickr photos of CTX1300A
Yep, that lone state of Maine is where I owned my first mc.