Mercedes-Benz SLK R172 (2011-2020) Front Upper Arm Inner Bush Caster Adjustable - PFF40-502G Made using our Black 95A Durometer Polyurethane with in-house CNC-machined stainless-steel adjustable sleeves and a matched adjusting spanner, they now include the geometry adjustment present in the original bushes, plus an additional 50% for extra control over your wheel geometry. This equates +/- 1 of front wheel caster. - NOTE: Price is for CAR KIT, NOT per bush… Powerflex price their bushes individually, but we have combined the quantities to make it simple!