These are printed footies for 1 inch angle iron. I used them to stop a table from scratching the floor. The corners have fillets to make them easier to install, should fit snugly but not too tight.
1 inch angle iron is 1in x 1in x 1/8in
25.6mm x 25.6mm x 4.00mm
I did a 100% infill at 0.16mm layer size.
The author hasn't provided the model origin yet.