Headphone automatic polishing production line 3D model is available on CGTrader for $39. Original author: chanway2012.
STP (STEP, filesize: 329 MB), MAX (Autodesk 3ds Max, filesize: 1.09 GB), IGE (IGES, filesize: 256 MB), DXF (DXF, filesize: 128 MB), DWG (AutoCAD, filesize: 235 MB), FBX (Autodesk FBX, filesize: 1.45 GB), SLDPRT (SolidWorks, filesize: 190 MB), PDF (PDF, filesize: 190 MB)