It creates a 5 x 5 square hole from the Terraformer to bedrock, whilst leaving all ores untouched and exposed. It is less efficient than using a Miner but is useful for making deep holes for mob traps. Be advised that both man-made and natural blocks will be destroyed; the only exception is the terraformer, which is left untouched.
1. Will crash the game if used within 15 blocks of an active miner-terraformer
2. Function will be erased if you apply electricity to it, e.g. putting it in a charge pack of some sort.
3. This is not included in the 1.1 release of the Technic Pack