If you have those wire shelves with adjustable height on round-grooved rods, you may have a need for replacement retainer sleeves. These are tapered on the outside, not tapered on the inside, with ridges inside that fit the grooves in the shelf supports.
Print two for a set.
When loading the model into your slicer, do NOT allow the slicer to "fix" the errors in the print - as doing this destroys the alignment of the printed part. Also, when loading - load as a single assembly or the slicer may "combine" sections of the sleeve.
Print with raft (1 or 2 layers) to get better bed adhesion
Each shelf typically takes 8 of these (2 per corner).
The author hasn't provided the model origin yet.