The KYB Ultra SR shock absorbers are mono tube gas shock absorbers, struts and cartridges. Assembled at the factory and then inspected to be sure they are exact you can be sure you are receiving a product that will consistently delivered a better than new handling and ride comfort feel.The Ultra SR shock absorber has been specially designed to compensate for the accumulated wear and tear on other parts of the suspension system, the Ultra SR is able to do this by using a patented valving with nitrogen gas system that is able to completely eliminate foaming, this is usually what causes shocks to fail even after a few minutes of operation. These are then able to provide a better ride and better steering response. The Ultra SR has been designed to give maximum safety for users who have high demands on road handling.Ultra SR is specially designed for excellent driving stability with maximum safety for the ambitious sports driver with high demands on road handling. Gas filled MacPherson.For