The original files were produced in Autodesk Inventor, and are in the "Autodesk
Inventor Files (Dynamic)" folder
 - They share an Excel file that contains parameter values, and changing the
    values in this file allows all components of the pyramid to be updated
    simultaneously
 - Opening the Pyramid Assembly file allows dynamic adjustment of the aperture
    mechanism

The original files were exported to STEP, SAT and 3D-PDF file formats, and
these are contained in the respective folders.