Will replace distorted and worn-out original rubber mounts to maintain car body and truck cab to bed alignment. Original rubber mounts are so soft they often , distort, and crush so badly they often fall off! And aluminum body mounts are too harsh for street use that they tend to break and cause other components to break.Energy's specially formulated Hyper-Flex(TM) polyurethane cab and body mounts combine the best qualities of both: they're soft enough for a smooth ride, yet rugged enough for the most demanding road or track.Most sets have a strong zinc plated steel ring molded into them - for added durability and when the application requires it.