Wera Tools - Bit-Check 10 BiTorsion 1Robust 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. Tough viscous bits for universal use. BiTorsion bits with Torsion zone where kinetic energy is diverted from peak loads. This greatly extends the product service life. This provides the best possible durability together with the matching holder.