That restriction does seem odd - odder still is that there haven't been any posts about 900s for so long. I can only say that the mini-blasters are so small that they hardly need any "mounting", and that they were rigorously tested in all kinds of enclosed situations and worked well because of their wide range and high power - mine work in conditions that at first sight seem impractical. I caught that note about the eight devices and wondered if they were confusing things with the 1100, which can take only eight devices to each extender, where the 900 is unlimited. While each of the 900's two mini-blasters can control any number of devices, i certainly don't see how the four cabled emitters can control eight! As I indicated Logitech are notoriously, and absurdly, bad at publicising their products. The awfully designed web site itself confirms that, and a run of the Comparison tool will confirm it all the more - they all come out the same!