1st Generation Mazda RX-7 and earlier cars have a recirculating ball-type steering system that utilized an ilder arm opposite the steering arm, to keep the motion parallel. This idler arm uses two rubber bushings that deteriorate with age and heat (next to the exhuast manifold). When they crumble to pieces, the two front wheels are not entirely on the same page so the car will wander and act funny. Replacement is easy and the improvement to handling is amazing comparred to deteriorated bushings. Price is for a pair, which is enough for one car.