High quality bits for Phillips screws with tiny diamond particles on the bit tip. This ensures a secure fit of the bit in the screw, reduces the contact pressure required and lowers the risk of slipping. Comes with Torsion zone - where kinetic energy is diverted from peak loads - and softer BiTorsion zone to prevent the bit tip from twisting under peak loads. This greatly extends the product service life; ¼" hexagon, suitable for holders as per DIN ISO 1173-D 6.3. Features and Benefits • For Phillips screws • BiTorsion zone to absorb peak loads • Considerable reduction in the risk of breakage, significant increase in service life • Diamond coating for a secure fit in the screw, literally bites into the screwhead to prevent cam-out • 1/4" hexagon drive (Wera connecting series 1) Contents 1x 851/1 BDC SB bits, PH 3 x 25 mm; 1x 851/1 BDC bits: PH 3x25