If you are ordering from motomachines, do not, repeat do not bother with the 40 dollar "adapters". They are just regular rizoma bar ends that ultimately will not work with the FZ/XSR's threaded inner handlebar. Ideally the best way to install Rizoma Reversible (and basically what motomachines wants you to do) would be on an aftermarket bar with the handles pushed in a bit to make room for the mirrors to mount on the very end of the handle bars (the actual handle bars) and not on a bar end cap. Or you can also mount them on stock, but once again you need to move the handle and controls inward, which is sort of a pain because you then have to either re-drill holes in the stock bar to accommodate the new location of the controls or shave the nubs down on the controls. There really isn't a quick easy way to install these mirrors on a fz07/fz09/xsr900 because they really don't make adapters as readily as available as CRG mirrors. Any CRG mirror adapters (including Rhinomoto) do not work because the groove/channel to take the mirror is too slim. The rizomas are much thicker than CRG mirrors.
I have Rizoma Reverse mirrors installed on my FZ07, and let's just say I wasted a whole bunch of time and money trying to find a way to install these. Ultimately I ended up going a unsafe route that I do not recommend.
Maybe things have changed since 2 years and there is an easier way to install those mirror, but I have no idea.
Rizoma knockoffs are MUCH, much easier to install than the real things.