Wera 05052575001 890/4/1 1/4'' Hex Universal Bit Holders are for the take-up of bits with " hexagon head drive as per DIN ISO 1173-C 6.3 while the retaining ring ensures an optimum fit of the tool in the holder. Wera 890/4/1 1/4'' Hex Universal Bit Holders are suitable for power screwdrivers with take-up as per DIN ISO 1173-F 6.3.