This is a stack-able drawer/holder for Lauterbach debugger (Power Debug E40), mountable to a rack (2/3 U size per drawer).
Perfect if you happen to run a board farm and want to save some space by stacking multiple debugging probes on top of each other.
The individual drawers are stack-able - just press them on top of each other. The 'stabilizers' can be used to make the very top drawer more robust.
To hold the debugger in place, the probe's debug cable connector is used to hold the device in place (see attached photos).

As the height of one drawer unit is 2/3 U (2/3 of the height of the standard 1U rack unit), one of the mounting holes is tall to compensate for any misalignment. This means that if you stack 4 drawers on top of each other, the top and bottom one will have the same alignment with the rack rail.

I have created this model in OnShape, feel free to check-out its document.

Note: The attached pictures may use an older version of the model, but generally the idea stays the same.