Leaving the magnetic holder in your drill chuck means it only takes a second to swap bits from one size to another. The strong magnet holds the bit firmly and helps keep the screw on the tip. Available in a range of sizes, the extra length of the longer bit holders means you can gain access to those difficult to reach areas. The universal shank is compatible with all 1/4 hex tool holders, standard drill chucks or quick change systems including Festool's Centrotec.