Phantom Block Penetration

You show a hollow plastic cylinder and a solid cylinder with holes in them. You place the smaller cylinder with the larger cylinder and pass a rod through it, completely and firmly sealing the smaller cylinder within the larger cylinder. Yet on your command the smaller cylinder penetrates the rod and magically falls off. Everything can be inspected at all times. Nothing is hidden, added or switched at any time.

The larger cylinder measures about 3" in height and the smaller one measures about 1.5" in height. The rod is chrome plated to a smooth finish.