Did you ever go to insert the SD card and.... woops... instead of sliding into it's slot, you dropped it into the innards of the printer? (Well, neither did I, but I ALMOST did and that was close enough.)

This little block fills in the gap around the card slot and USB connector.

Not sure yet how consistent the connector and card slot positions are between printers over time. The first version (1) of this thing fits the Bibo 3D I received August 2018.

There are two (0.2mm) bumps on the left side to make it fit snugly. Easy to take it out with needle nose. Sand the bumps down and/or adjust scale very slightly, if needed, for optimum fit.