I really wanted this little contraption to please but after 45 minutes of trying to drill countersunk pilot holes and the bit got stuck in wood I ended up throwing them it in the trash. The set screws don't hold the drill in place and the long shank wobbles. Great concept but poorly executed. I had to believe some of the other reviews. I wouldn't buy it again and honestly don't recommend it at all. look elsewhere As for me, I just go back to one drill with a countersink and another drill with a screwdriver.