It's awesome, lots of kudos to the creator for doing so! Personally I'm more likely to buy things where the authors makes the schematic/3D object/whatever available for free for the DIY people out there, and those who couldn't otherwise get the thing to them for one or another reason.

> I know there are other dogs and owners out there facing similar struggles. That’s why I’m sharing this design for free. While it’s not adjustable by design, it should fit medium-to-large dogs as is. If needed, measurements can be adjusted using the scaling feature in your slicer software, but some slots, like those for the straps, might deform in the process.

Only missing for it to be a parametric design people could easily adjust based on their own measurements, but trivial to change yourself too, so again, lots of thanks to the author for improving the whole world, not just a tiny piece of it.