Wera 05066073001 867/1 Z 1/4'' Hex Torx Insert Bit w/ Holding Function are high quality bits for recessed Torx screws. Wera 867/1 Z 1/4'' Hex Torx Insert Bit w/ Holding Function work because the wedging forces resulting from the contact pressure between the drive tip and the screw profile securely hold the screw on the tool. Wera 867/1 Z 1/4'' Hex Torx Insert Bit w/ Holding Function are suitable for holder as per DIN ISO 1173-D 6.3.