it is worthwhile to spend a little more because this drill head wobbles neither nor slackens. The drills are kept accurate. However, it should be noted that the hexagon naturally in a cordless screwdriver for example. IXO only infected. He holds the drilling well, is but not fixed and therefore> not pull the reverse rotation, otherwise he is' out ... :-)> Hitachi chuck ZKBF 10 mm and adapter 1/4 "" 6-point, 752 082 "