It is an iris mechanism(shutter structure). Most parts are designed for laser cutting and cnc machining. You can 3d print these parts too. There are DXF ,STEP and STL formatS files.DXF files are for laser cutting(part thickness is 2 mm); STL and STEP files are for 3d printing.There are some screw holes, and you should manufacture these screws with a tapping tool. And there are some bolts which you can get on market easily.Ignore the FBX and OBJ format files, they are only used to meet cgtrader's requirement.More: https://www.tanerxun.com/mechanical-iris-shutter-mechanism/.html