Ultra-light, ultra-strong eccentric upper clamp for ball-bearing (without using composite hub), CNC-machined from premium Swiss 7075 T6 aluminum. Eccentric top clamps enable movement associated with the rear axle 1mm ahead or rearward according to the clamp orientation. A shorter car rotates faster in sluggish corners and it has now improved ahead traction. An extended vehicle is freer in high-speed corners and will feel more linear, particularly during quick means modifications. Also black colored colored coated for long life and fashionable look. Identical left/right. Fits aluminum backside bulkheads with fast & simple journey height modification. Two pieces are required for create. Fits X12 and X1.