I have 120mm, 160mm, and 200mm wide varieties.
To make a shelf you must print:
* left and right bracketes
* a crossbar of selected length
* a bottom shelf of selected length
Created in Onshape:
https://cad.onshape.com/documents/3d0668a638105db58510f19e/w/f02bbc2b93d51e0a5ac90d0e/e/45afeda40981ddbb3ff16148?renderMode=0&uiState=68ec32dbb94f26ff8b2cbfcfhttps://cad.onshape.com/documents/3d0668a638105db58510f19e/w/f02bbc2b93d51e0a5ac90d0e/e/45afeda40981ddbb3ff16148?renderMode=0&uiState=68ec32dbb94f26ff8b2cbfcf
The author marked this model as their own original creation.