This model is a cutting guide to help you dress coaxial radio cable for a crimp-on BNC connector. It is for Amphenol part number 112533, which suits RG-8x and LMR-240 50 ohm cable.
As shown in the attached picture, Amphenol specifies exact distances for removing the outside insulation of the cable, the braid and the inner insulation. If you lay your cable in the guide, the end of the guide is where you should cut the outside insulation. In the sides of the guide there are two very narrow slots, which you might need to widen with your cutting tool if it is thicker than the slots. The slot closest to the end of the guide is where you should cut down to the inner conductor. The slot furtheset from the end is the guide for trimming back the braid of the coax.
Once the cable is dressed it needs to be crimped with an appropriate crimping tool and corresponding die.
The OnShape modeling link is here: https://cad.onshape.com/documents/bb318d77901799d8ea481be8/w/21e65aa6ef6dc38ddf08f15e/e/26cb614d66082fb9a5d057c3?renderMode=0&uiState=64830ee01cfbfe1b4e5b2750
I printed this on a Prusa Mini+ using PET-G filament, but PLA could easily be used, too.
The author marked this model as their own original creation.