Wiha MagicSpring Torque Control Blades are designed to be used with Wiha TorqueVario, TorqueFix, and iTorque, Screwdriver handles only. They are not for use in Wiha in insulated torque handles, esd torque handles, T-Handles, or torque wrenches. Wiha MagicSpring retaining spring TorxPlus screws are kept firmly where you want them. The retaining spring MagicSpring together with a thin cover disc, is laser-welded to the tip of the blade. This acts as a clamp between tool and TorxPlus screw, so that the latter is firmly gripped by the tip of the blade. This is especially beneficial when turning particularly small screws or when screw in areas that are difficult to access. The torque blades can be inserted into the Wiha torque screwdriver handles to create a solid screwdriver handle with a torque setting. The fixed blade elimiates the potential for play and wobble caused when using a bit or bit adapter. The fixed blades have markings with their size and max torque ratings for easy identification.