The file 'Fishcaller 3D Printer Model' is (stl) file type, size is 1.4MB.
Fishcaller.
Works like: https://www.youtube.com/watch?v=dEw1oODA4BU&feature=youtu.be
You need:
https://www.mcmaster.com/#standard-rounded-head-screws/=78905acdfe584053b9f3e493019ba0d9jkr7xvcn
https://www.mcmaster.com/#hex-nuts/=78905acdfe584053b9f3e493019ba0d9jkr7zhzd
Have a good catch!