Where is the IR receiver on the Tivo Roamio?

I have a basic TiVo Roamio (500GB model). I think I have decided, for now, to use my existing IR harmony remote.
I need to move the Roamio into my media closet, so I will need to place an IR blaster in front of the sensor.
Where would the sensor be located on a Roamio?

TIA