The rear nut has an external spline which mates with the internal spline on the front nut, preventing rotation. For an anti-backlash nut to work correctly it must either push the two nut halves towards one another or away from one another to eliminate any backlash. The C style nut eliminates this backlash by pushing the two nuts away from each other. The compression spring, which rests on the front nut, applies a force to the ring which transfers the force to the rear nut. This action forces the rear nut away from the front nut, removing the backlash between the two nuts.