That's the Ultra Light Bike Mirror: http://www.amazon.com/Ultra-Light-Bi.../dp/B0011VQJU2

Rivendell just calls it the German Mirror: http://www.rivbike.com/search/run?query=m (You probably should be able to get it at a cheaper place than Rivendell, though).

I like it. My options are limited with my handlebar situation. I tried a couple of the cheap chrome mirrors that look like they could be made for mo-peds because they would work with my bars, but I didn't like them. This one will shake a lot unless you really tighten it. I've used the Mirrycle with past bikes, and this one is better in some ways. This mirror is much lighter. I felt the Mirrycle (bolt in the bar end kind) had a mount that was perhaps more solid, and allowed easy adjustment even while tight enough not to jiggle. I've seen these German mirrors mounted horizontal for a very wide view, but I can see farther back this way, and it wouldn't really work on my bike the horizontal way anyway. But the shape is better than a round mirror for getting what you want to see with a smaller footprint, although it is not as big as some of the other popular mirrors on the market.