I made some mirror extenders out of some 1/2" wide aluminum bar stock that I had. I was going to drill and tap the mirror end but found out that the threaded end is left handed threads. So I drilled out both ends used the backing nut for the mirror end and bought metric bolts from Lowes for handlebar ends. They are apparently 3" long. I can't start to tell you how much difference in makes in being able to see behind you. I would recommend mirror extenders for everyone!