I purchased this particular mirror to replace one that had fallen out. When I brought my bike back in March, it came with these mirrors and they felt secure. Unfortunately, despite checking the security of the fitment on several occasions I lost the right one first, then the right a few months later. I have after market Pro Taper handle bars, which has a 10mm aperture, where the Oxford mirror comes with a 12mm and 18mm expansion bushes, say no more. I especially like the anti-glare convex glass, which provides an excellent level of visibility and the excellent range of mirror movement, to position it in the desired sweet spot. The mirror is easy to install, well, once the hole has been drilled out, and fits securely. Top tip, check the fitting every so often, giving it a tweak with an Allen key to nip it up if needed. There isn't anything I dislike about this mirror and I highly recommend it. As always, I received an excellent level of service from sportsbikeshop, thank you. Your loyal customer, Steve.