1/4" (6.35mm 6.3mm) hex shank to 4mm 4 mm socket driver bit adapter for precision (system 4) hex bits magnetic holder Has a magnet to hold 4mm micro / precision bits Approx 25mm (1") long, so doesn't wobble like the longer bits Functionally similar to the Wiha 75802 adaptor but not identical Product Description A micro bit 1/4" insert adapter for standard 1/4" drive tools. Note that this is a precision bit holder meant to be used with precision bits and not a power tool bit. It is meant for delicate work, not high torque applications. Uses magnet to hold 4mm micro bits ~ 1" long - so it is a short bit Package includes: Only 1x bit adaptor. No packaging or other items are included in this sale.