Bit-Check-30-Bi Torsion-1-Set-30-Piece-Wera-05057430001-p-The-Wera-Bit-Check-30-Bi Torsion-1-with-Rapidaptor-is-designed-for-compact-&-organised-tool-storage-p-p-Utilising-a-unique-combination-of-special-material-hardening-&-precision-manufacture-Bi Torsion-bits-are-designed-to-prevent-premature-wear-&-dramatically-extend-service-life-The-patented-Torsion-zone-absorbs-peak-stress-loads-that-normally-destroy-bits-BTZ-Extra-Tough-bits-are-suited-to-hard-metal-jointing-threaded