Marker holder for edsal garage shelf with rivets

This is something I threw together to store sharpies cap down that slides into the rivet holes that the edsal/muscle rack garage shelf I have for my printer.

This could be used for other tools- it has an inner diameter of 14 mm (OD=16 mm), is 60 mm deep and holds the tool 15º from vertical. It has a 'vented' bottom to stop things from getting stuck.

I believe that the company that manufactured the shelves I used sells similar ones under different brand names, so if you want to check make