I had one on my Focus. The Focus Central CAI does the same thing that the Volant does, but the Focus Central unit has much lower build quality. The airbox is made out of cheap fiberglass with an unfinished look. Mine didn't come with the hardware to mount the MAF housing to the box or any kind of instructions to install it (even tho it is pretty simple for anyone with a little bit of automotive knowledge). The cone filter sits at a very odd angle in the airbox due to the lack of proper design. I couldn't even get the Focus Central logo to stick to the outside of the airbox. I can't believe they charge $170 for it. Even I could have come up with a lot better design than that.
For only about $50 more you can get the Volant unit that looks and is built much better. That's what I wish I had done.