The portable hole is a wand focus that will create a 3-by-3 tunnel through terrain until it either reaches its maximum length, the user runs out of vis or it meets a hollow space. Like other foci the portable hole can be upgraded with a Focal Manipulator.
Blocks can be blacklisted from being permeable to this focus via a blacklist in the config files.
Thaumcraft 4.2 Tutorial [Portable Hole]
This video was created by Zautos