Hi. How are these (pic below) used? Does anyone know a site that shows how? Can you use this for only a two tier cake? How about 3 tiers? Thanks in advance.

The loose "caps" are placed on the pillars (slide them onto the bottom and push them all the way to the top, for now). Then just push the pillars into the lower tier cake. Slide those caps down onto the top of the cake. This gives the illusion that the pillars is just sitting on top of the cake instead of being pushed down into the cake. Set the upper tier cake plate into the pillars.

You can also use them just "plain" .... without the caps.