This is a simple parametric 3D Printed Bearing. This particular bearing is made using 5mm balls and has a 1/2 inch bore. You can create a bearing of any shape and size by cloning and updating the OnShape model found here: https://cad.onshape.com/documents/4ed202a38ada8e1dfccba891/w/bd3bf9fe0e32759fc8b1d73c/e/bee50378488d9af1c789570f?renderMode=0&uiState=63287791c4561748e57c08f7
The author hasn't provided the model origin yet.