The Horizontal Rear Bodypost Set (HRB) lowers the center of gravity.
This improves the handling and cornerspeed of your car which leads to faster laptimes.

Furthermore the bodyshell will become more stiff in the rear end section and has less deflection at high speed at thus.

Fits all A800 models beside A800FX. 

1x C05-H
1x AM126
2x SB3x8