This line of Backstops / Turnstiles is made with high strength, ensuring its full operation in high torque requests. The TTFZ line is supplied with lateral keyways on both sides of the cover, allowing it to be perfectly locked in the housing. Its locking core, provided with a roller ramp system, is guided laterally, allowing for balance of forces at the moment of actuation. The TTFZ line does not replace bearings, and cannot receive radial and/or axial forces. Therefore, for its perfect operation, this line must be mounted together with a bearing.