Lego Education kit comes with the caster & steel ball '2000702' but not in commercial one.
Those aren't available in many countries so here's the next best solution.
This caster is for the marble/glass ball size 16.1mm (5/8 in is a bit loose and 2/3 in might be a tight).
The part is needed to make e.g. Robot Education rover unit out from the commercial EV3 Mindstorm 31313 kit. Please, notice this one is a bit shorter that the original one as edu kit has the bigger wheels that the commercial one.
Category: Construction ToysThe author marked this model as their own original creation. Imported from Thingiverse.