Wera Bit-Check 12 BiTorsion 1, with Rapidaptor is designed for compact and organized tool storage. Utilising a unique combination of special material, hardening and precision manufacture, BI-TORSION bits are designed to prevent premature wear and 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 fasteners and general use. The holder with quick-release chuck offers press-in auto-lock and rapid one-handed bit changes for insert and power bits. The holder spin sleeve allows the steadying of the screwdriving. Wera Bit-Checks feature a compact design to safely store bits and bit holders in a case that provides fast and easy tool selection. So slim it can fit into your pocket. Drive and size are colour coded for easy selection of the right bit