Rambling pin #2
Exploring the first version of the rambling pin lead us to this technique - an even smaller version using the newish 1x1 round plates with holes.
To find the different pieces needed for this technique you can search LEGO's online Pick-a-Brick for the design ID's. We link other market places directly on each individual piece page, which you can find below.
At exactly three plates high you got a very useful little technique.