7pc Bi Torsion Diamond Coated Bit Check Set. Bi Torsion Diamond bits (BDC) significantly extend service life & prevent cam out. Microscopic diamond particles literally bite into screwheads preventing slips. The two unique Torsion zones one in the bit & one in the holder work together to absorb peak loads placed on the bit extending bit service life. Diamond bits are also hardened to a higher degree than standard bits extending life further. Unique Rapidaptor bit holder locking system for quick & easy one hand bit change. Standard 1 / 4 hexagon drive. With Bi Torsion Rapidaptor holder for ultimate service life 1 / 4IN Hexagon drive 25 mm bits 6 Bi Torsion Diamond Bits 2 x Slotted 1 x 5. 5mm 1 x 6. 5mm 2 x Phillips 1 x PH1 1 x PH2 2 x Pozi 1 x PZ1 1 x PZ2.