Board Thread:Questions and Answers/@comment-95.178.132.13-20130611172247/@comment-10703376-20130611194836

The block breaker will destroy the block it is facing, unless it is bedrock or a Personal Safe. To break the block, it must be given a redstone pulse. It is a good method for an automatic cobblestone farm, where there's a cobblestone generator. It will spit the item broken out the back of itself, unless there is a Pneumatic Tube there with a legitimate destination. It will put the item into the tube.