PFF19-2202GBLK Front Arm Rear Bush Caster Adjust has been designed around our unique on-car adjustable Nylon/Polyurethane Ball-Joint combination for more direct steering input and improved cornering and braking. The offset bore allows for +/- 0.5-1.0   of caster adjustment with the supplied spanner, to assist the fine-tuning of the side-to-side caster settings.  Vertical stiffness is increased by 250% over standard rubber.