https://www.grainger.com/product/38XZ72?cm_mmc=PPC:Google-_-GlobalExport-_-SB-_-Acquisition-_-2020009&gclid=EAIaIQobChMIpsmd4771gAMVUffVCh10Xgf3EAQYAyABEgKr_fD_BwE

This is a slotted angular post. They are used as posts for metal shelves.

I have a few pieces from 1 meter to half meter. I repurposed some of them as tool holders. You fix the piece HORIZONTALLY on the wall. And use the holes to hold screwdrivers and such .