This is a replacement part that in our Black Series application is over 200% stiffer than the original rubber bush to withstand increased loading seen by this position on the car. For a caster offset version please use PFF5-1901GBLK.
 
OEM Part Number: Bush = 31126855743 / 31 12 6 855 743
OEM Part Number: Arm = 31126855741 / 31 12 6 855 741
OEM Part Number: Arm = 31126855742 / 31 12 6 855 742