Wera 05071011001 3851/1 TS Stainless Steel 1/4'' Hex Phillips Insert Bits feature a torsion design to protect against premature wear, the stainless steel on these bits prevents the fomation of unsightly extraneous rust. Wera 3851/1 TS Stainless Steel Phillips 1/4'' Hex Insert Bits are suitable for holders as per DIN ISO 1173-D 6.3.