Edit 2020-04-12:
I have made a longer Version with half the height (long_strap.stl). Thank you for the feedback @timmy_d3. I decreased the height to get more flexibility. If you want to adjust the height/flexibility you can just scale the Z-height.

The original strap from the picture is still available under new name (original_stap.stl).

And I have added a version as long as the original, but with the new height of the longer version (short_strap.stl)

Original Summary:
I have no access to the Prusa mentioned straps, so I needed to create my own.

This is my Prusa Face Shield TPU Strap. AND it is my first ever TPU print... So please send me comments, if there is something to optimize.