SRS-Concept - ADJUSTABLE LOWER CONTROL ARM BUSHINGS (4283)You now have more adjustability when it comes to your caster. These bushings let you fully adjust the caster of your car by moving your front wheels forward or backward. You only need to remove your old lower control arm bushing ( called lollipop ) and install ours. You should verify if the round parts of your control arms that slide into the control arm bushing are in good shape, it may be rusty and the diameter must be 20mm, not more and not less.