855/1 TH SB bits, 3 pieces 3x 855/1 TH bits: PZ 3x25 mm, PZ 2x25 mm, PZ 1x25 mmPremium bits with torsion zone into which kinetic energy is dissipated during peak loads. This significantly increases the product life. Extra-hard. 1/4", hexagonal, suitable for holding tools as per DIN ISO 1173-D 6.3.