Advantech UNO-148 - Idoor Extension Kit (UNO-148-ID1 EA)

UNO-148 User Manual 42
9. Return the back cover and gently screw it into place.
3.7.2 iDoor Extension Kit (UNO-148-ID1EA)
You can additionally install 2nd stack iDoor extension kit (PN: UNO-148-ID1EA) on
UNO-148 to expand its functionality:
The accessory list for iDoor extension kit (PN: UNO-148-ID1EA)
5 x M3x4L screws for extension kit installation