This is a reference file with scale drawings, and 3D models to help you make backpacks for the Windam. The files are not for replacement parts, they lack details of the original parts.
This contains
2 PDF scale drawings, one of the backpack and one of the back.
STL, STEP and f3d files to allow you to test fit your models.

These files are free to use as you wish, but please do not sell on the files, the reason they are public domain is so that if you want to sell your creation from this then go ahead.