Converts dual damper rod and damper rod cartridge to true high performance monotube cartridge forks Improved resistance to front brake dive Improved front end stability, cornering, and bottoming control Limited lifetime warranty True high performance front suspension has made its way to the Harley aftermarket. Progressive Suspension’s state of the art Fork Cartridge Kit represents the peak of performance front end handling. The kit features a set of gas charged Monotube damper cartridges and a set of custom tuned fork springs in stock and lowered versions. Replaces all of the OEM fork internals.