This drill and other drills I have purchased work as they should. These bits won't drill dozens of holes in old concrete. You'll be lucky if you get 5 or 6 holes out of a bit. The pilot jet may break or the locking pin may break or fall out, this is not necessarily a fault caused by a broken jet. This drill is not magic, it drills holes of all shapes and sizes in concrete. It will drill through steel rebar, but this must be done carefully and will dull the drill significantly, so use a rebar cutter in these areas if possible. It frustrates me that people are giving three stars or less to this beat as it is worth every penny and I am lucky to have access to them. These exercises are profitable if you offer your job correctly. Just my opinion.