897/4 R SB Rapidaptor BiTorsion Universal Bit Holder, 1/4", x 75 mmUniversal holder for bits with hexagon head drive as per DIN ISO 1173-C 6.3 and E 6.3 (ISO 1173). BiTorsion holders by Wera have a torsion spring that absorbs low peak loads during screwdriving jobs. The combined use with BiTorsion bits and their torsion zones extends the service life of