Zinoro M13 60H/100H (2015 - 2019) Rear Upper Arm Inner Bush - PFR5-1311 PFR5-1311 is made from our Black Series 95A material for ultimate chassis control. Replaces inner position only on rear upper arms, the outer position is a spherical bearing. - NOTE: Price is for CAR KIT, NOT per bush… Powerflex price their bushes individually, but we have combined the quantities to make it simple!