Print in PETG using standard PETG printing parameters or some other tough plastic like ASA.  I used Inland PETG and printed with Prusa's generic PETG parameters and infill 50%.  Part is thin, so infill 15% will be fine.  But, higher infill is desirable for heavier loads.

BE CAREFUL PULLING OFF BED.  Adhesion is fine on smooth plates.  No brim/raft required.  Part is liable to break in thin places if pulled off plate without care.

Superglue parts down the seam to assemble.  Parts also work fine without superglue.

I use this to hold my split keyboard(s) and gaming controller(s).  I see potential use for figurine collections, holding small containers, and holding/displaying other things.