Robust Bit-Check by Wera. Bit-Checks provide a quick overview of the tools available. Bits not needed are simply reinserted into the set and do not get lost. Simple transportation e.g. in the shirt pocket. Extra-hard bits. BiTorsion bits with an elastic Torsion zone - where kinetic energy is diverted from peak loads - and softer BiTorsion zone to prevent the bit tip from twisting under peak loads. This greatly extends the product service life. It provides the best possible durability together with the matching holder. Comes with Rapidaptor technology, which allows bits to be attached without any need to actuate the sleeve. The removal of the bit is simple, just by pushing the sleeve forward - for rapid bit change with just one hand. For the take-up of bits with 1/4" hexagon head drive as per DIN ISO 1173-C 6.3 and E 6.3. For insertion in the power screwdriver or for use in the chuck of an electric drill.