VDE bit holder: Quick and precise adjustment of the torque values by a digital display, variably adjustable torque covers a wide range of applications. Bit screwdriver: Calibration protocol with an accuracy of +/-6% for all torque tools from Wiha. Ergonomic handle: For work that is easy on hands and muscles, recommended by doctors and therapists of the German Campaign for Healthier Backs! slimBits tested at 10,000 V AC and approved for 1,000 V AC. Electrical screwdriver: To ensure safety when working on live parts it is necessary that NO standard non-insulated ¼“ bits fit into the bit chuck. Torque screwdriver: A clearly audible, physically perceptible signal emitted when the torque is triggered guarantees process safe torque mechanics (protecting against damage to materials and eliminating the need for retouching)