There's about a dozen USB remotes sold as a USB Follow Focus System, but this particular one lacks lens focus controls and just throws in some basic functions. This one was designed to mount close to your rig handle so that you can access common settings like ISO, Aperture, Shutter Speed, Zoom Focus, Start / Stop Video Mode, etc.
Don't be confused by some of the listings, it's obvious they don't know what they are talking about and list it to be a follow focus controller (wrong!). This looks like the Okii MC1 controller, except it's about $100 dollars less. I like this particular handle design over those ugly round Canon USB Follow focuses but i'm still not sold on paying so much for this type of remote. You can find additional info about these Canon USB Video Remotes on eBay following the link (click here).
Canon mini USB Camera Control