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 three 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. Hex shank.