Koni uses hydraulic technology for damping control where all of our other performance shocks use hydraulic and high pressure nitrogen gas. The effect of this in our opinion is that the Koni provides a plusher and softer ride while providing excellent control. Konis are firm, but they transition so smoothly the perception is that they are soft. Konis are also adjustable so that as they wear with age, you can adjust the rebound damping control to compensate. (The shocks must be removed from the car in order to adjust them). Lifetime warranty.
Additional Information: http://www.ipdusa.com/Shock-Warranty-Information/pg-22