These devices use radio frequency communications, not infrared; so they
don't need to have direct line of sight. They are highly range-limited
though so your plan may or may not work.

"Hillbilly" wrote in message
...
I've never used wireless mice or keyboards before and need to learn how
reliable they are when used in "proximity" to a small form factor PC that
will be mounted "behind" a HDTV mounted to a wall. I'm planning to put the
keyboard and mouse in a box mounted to the wall just below the HDTV hung
on the wall inches above. When the lid of the box is opened it will swing
down like a tray holding the keyboard and mouse but I don't know if this
will be allow the keyboard and mouse to operate?

How would Microsoft's wireless keyboard and mice work then? I'll continue
to do some looking around but any help to determine how these things
actually work so I can know the range and limits will be very helpful to
me thank you...