SuperPro Polyurethane spring collars for TR2-6. Polyurethane is the best solution for road use. It gives improved location without having a detrimental effect on noise levels or a harsh ride. Added advantages are improved longevity, and unlike rubber, it is not affect by U.V. light, water, salt, oil, or petrol. Supplied with a steel sleeve where neccessary and the all important grease that must be applied on both the inside and outside of the bush to avoid squeaking and premature damage to the bush.