855/4 TZ SB bits, PZ 2 x 50 mm, 2 pieces 2x 855/4 TZ bits: PZ 2 x 50 mmHigh quality bits with Torsion zone - where kinetic energy is diverted from peak loads. This greatly extends the product service life. Tough viscous, for universal use. hexagon, suitable for holders as per DIN ISO 1173-F 6.3.