The file 'LM2596/LM2577/XL6009 Buck DC Converter Enclosure 3D Printer Model' is (scad,stl) file type, size is 543.49 KB.
This is an enclosure for the popular cheap DC-DC converter modules (LM2596/LM2577/XL6009).
It's designed for 43mm x 22mm board, but can be easily resized and customized in OpenSCAD.