All of them.
It works. Even on my 10,000 RPM Raptor Drive.
Much less vibrations than fans of similar size and price. Even holding it, almost none, and the rubber feet will dampen those. At most angles, higher-frequency noise is very low, and the lower-speed settings lower the noise frequency spectrum into a range that is less noticeable.
Worked perfectly right out of the box. Nothing to install, nothing to modify. I highly recommend this for extending any USB item beyond 16 feet.
It's made of nylon so its light enough to carry around in a pocket or pack ... seems well made and plenty of room for 6 flash drives ... I also carry some SD photo cards in it, but they are just loose in there