Whilst I agree that it was, obviously not a question (though the subject
was) - it cannot be considered an answer, either (unless we consider the
possibliity that the OP is mad and is talking to himself...)
And have you actually done some research and, having drawn a blank, posted
here as a last resort?! Don't bother answering that, because I know damned
well that you didn't! It took me exactly 30 seconds of searching Logitech's
website to find the answer to your question (and, no, I'm not going to tell
you what it is, you can do your own research!)