This is a bushing kit designed for use with Rancho's Track Bars. The kit includes D2 synthetic high articulation bushings. They come with special construction with durable inner bearing material and a softer outer material. The inner material ensures improved rigidity, while the outer material significantly reduces NVH (noise, vibration, and harshness) for more comfortable driving experience and better handling characteristics. Plus, the bushings are self-centered and grease-free in order to guarantee silent, maintenance-free operation.