Ultra-light, ultra-strong eccentric upper clamp for ball-bearing (without utilization of composite hub), CNC-machined from premium Swiss 7075 T6 aluminum. Eccentric top clamps enable movement of this back axle 1mm ahead or rearward depending on the clamp orientation. A shorter automobile rotates faster in sluggish corners and contains enhanced forward traction. A lengthier car is freer in high-speed corners and will feel more linear, especially during quick way modifications. In addition black coated for very long life and trendy look. Identical left/right. Fits aluminum back bulkheads with quick & effortless ride height adjustment. Two pieces are required for assembly. Fits X12 and X1.