A system for fixing a wire (4) to an external fixator element (3), wherein said system comprises:an external fixator element (3) having at least one surface (31) and at least one opening (30) extending from said surface (31),a wire (4) adapted to extend through bony structure and to be fastened to said surface (31),a bolt (1) having a shaft which comprises a threaded section (10), a head section (11) and at least one clamping element (12, 14) wherein said bolt (1) is adapted to extend through said opening (30) and said at least one clamping element (12, 14) accommodates and clamps a wire to said surface (31) with a clamping force,a nut (7) to pull said bolt (1) against said surface (31) the external fixator element (3) with said clamping force, anda counter torque tool (2) to provide a counter torque while fastening said wire (4) with said bolt (1) and said nut (7) to said surface (31).Said bolt (1) comprises a counter torque opening (13) and wherein said counter torque tool (2) comprises a bolt section (20) which is adapted to engage into said counter torque opening (13) of said bolt, and wherein said bolt section (20) has preferably a cross-section which is complementary to said counter torque opening (13).
