Energy suspensions polyurethane bushings
Energy Suspensions Hyperflex bushes in short
Suspensions bushes are under a lot of stress. Bushes insulate the vibrations and noises from the chassis, and also absorb the hardest shocks so parts wont break. The bushes need to be strong enough to prevent un-wanted wheel movements, but soft enough to be able to absorb the shocks which could break things.
The original bushes on a car are made from rubber which is very soft, and deteoriates over time. Hyperflex bushes are made out of polyurethane which allows 25 to 30 % stiffer bushes without sacrifycing other characteristics.