This key is used for assembly and disassembly of the torsion bush nut on the front axle of Citroën models from the 11CV and 15CV range. The key fits precisely on the hexagon of the nut and distributes the applied force across the contact surface. This supports safe release of tight connections and helps prevent damage to the nut and surrounding components. The tool includes a square drive for use with a torque wrench or breaker bar. Its dimensions are matched to the original torsion bush nut and allow targeted work on the suspension and axle system in a professional or specialist workshop environment.