I have one and it works wonders. I always start with the nock end and then square the insert end before installing the insert, and finaly the insert it self. Just for the heck of it I screwed on a broadhead the other day on an arrow that everything had been sqaured except for the insert itself and spun it. I wasnt too happy, I had quit a bit of wobble when I spun it. I unscrewed the broadhead and squared the insert, wala no more wobble. I was once again a happy camper.