Wera 05053457001 899/4/1 1/4'' Hex K Universal Bit Holders are for the take-up of bits with " hexagon head drive as per DIN ISO 1173-C 6.3 and comes with a stainless steel sleeve for very special corrosion protection. The retaining ring ensures an optimum fit of the tool in the holder. The strong permanent magnet holds the bits absolutely securely. Wera 899/4/1 1/4'' Hex K Universal Bit Holders are suitable for power screwdrivers with take-up as per DIN ISO 1173-F 6.3.