28531 is a T15 MagicSpring Torx TorqueControl blade. Used for Wiha in insulated torque handles, esd torque handles, T-handles, or torque wrenches. Wiha MagicSpring retaining spring Torx screw is kept firmly where user 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 Torx screw, so that the latter is firmly gripped by the tip of the blade. This acts as a clamp between tool and Torx 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 blade can be inserted into the Wiha torque screwdriver handles to create a solid screwdriver handle with a torque setting. The fixed blade eliminates the potential for play and wobble caused when using a bit or bit adapter.