It's a Rii Mini Keyboard i4, and my concern is that it's a microphone. I just noticed the hole and think I'm probably wrong in what it is considering how big a deal it would be if it was a mic that isn't advertised.
What could this hole be for or what is it? Thanks in advance, hope this doesn't violate any rules.
Well, you're in luck, as I happen to own this exact model, which has the same hole.
Taking it apart is quite easy, just 6 screws and some plastic tabs hold it together.
Here's the components on the underside of the board beneath the hole (these components face the rear backplate)
And if I pry the case apart a bit, I can't see any components directly beneath the hole, it's just bare PCB.
As far as I can tell, no microphone is present. The hole is likely a product of the injection molding process for the outer case.
One thing to note about this device though; while the ergonomics are great and its been reliable, I notice that my left hand wrapping around the case can sorta block the mouse pad signal to the dongle (about 6 feet away), so I need to hold it in a way that the transmitter isn't blocked by my hand to move the mouse curser smoothly.