I bought a Kano Build-Your-Own-Tablet kit a while back and decided that I wanted to build it as a dedicated jukebox. The heart of the kit is a Raspberry Pi, so my choices in software were limited. SilverJuke, though, which is in the repositories or can be compiled from source, turned out to be near perfect. My only trouble was that the audio jack on the kit is buried inside the clear plastic case. To be able to access it outside of the kit, I needed an external audio jack. Rather than drill a hole in the case, I designed this little gadget. It clips into the oval opening where the original speaker was located and accepts a panel mounted 3.5mm stereo audio jack. A matching 3.5mm stereo plug is run through the hole in the adapter. One end is soldered to the jack and the other end plugs into the audio jack on the Pi.
tl;dr: It's an audio expansion port for a Kano Tablet kit.
I recommend printing it in the orientation presented. Yes, this takes a lot of support, but the layer lines are oriented perpendicular to the lines of force on the clips so that they don't break when you try to clip it in place. The lid is glued on after assembly.