To use this Wera T-handle hex tool, simply select the right size for your screw. Hold the tool firmly by the T-handle, place the blade into the screw head, and turn to tighten or loosen. When using the additional short arm for high torque, make sure to use it carefully to avoid over - tightening. Always keep the tool clean after use. You can wipe it with a dry cloth. Store it in a dry place to prevent corrosion. Check the blade regularly for any signs of wear or damage, and if needed, replace it to ensure the tool's performance.