This custom 3D printed piece is made specifically for the Boxy Pixel machined Game Boy Advance aluminum housings. It locates the micro or Type C USB board needed to install a rechargeable battery within the device. The micro USB fits into the battery housing, and a rechargeable battery fits on top. It simply fastens using two machine screw fasteners.
The micro USB electronic board shown in the image is NOT included. Color may deviate from what is shown.