Screens without mm

[SevereOverfl0w]

I'm using a projector, which has it's xrandr line like so:

DP1 connected (normal left inverted right x axis y axis)
   1920x1080     60.00 +  50.00    59.94    24.00    23.98
   1920x1080i    60.00    50.00    59.94
   1600x1200     60.00
   1680x1050     59.88
   1280x1024     75.02    60.02
   1440x900      59.90
   1280x960      60.00
   1152x864      75.00
   1280x720     119.99    60.00    50.00    59.94
   1024x768      75.03    70.07    60.00
   832x624       74.55
   800x600       72.19    75.00    60.32    56.25
   720x576       50.00
   720x480       60.00    59.94
   640x480       75.00    72.81    66.67    60.00    59.94
   720x400       70.08

automirror is unable to detect this screen for some reason. I think it's due to the lack of mm.