The Festool 490294 FastFix eccentric chuck is a godsend for those who often work with drills in hard-to-reach places! The great thing about this device is that it allows you to drill and screw in places that a conventional drill simply cannot reach. You can literally work right up against walls and in the tightest of corners. The FastFix system lets you change drill functions in seconds. Just click and you're ready for another job. No need for separate tools, saving you time and money. Another plus is its versatility. This chuck fits all current and previous Festool drill models with FastFix interface. These include the T+3, C12, TDK, TDD and CDD.