This is a gib lock for most BF20 milling clones out there. The Grizzly G0704 is a popular American version of this milling machine. These are prone to breakage if a way movement crashes into one. This is a good replacement. Locks just fine without breaking when tightening. Large one for Z, smaller one for X and Y if you so choose.
I printed these in PLA with 10 perimeters.
The author marked this model as their own original creation.