Totally NEW DUAL COMPOUND: Innovative co-molding production technology which is patent pending by SKF. The rubber compounds are new and different from our previous aftermarket green seals. New metal insert and totally re-designed scraping and oil sealing lips. Open wound DS spring: this is not just a stretched std. spring but a dedicated fork seal spring with open winding. Benefits: constant force over time with no accumulation of debris between coils. Improved followability capability of the seals to conform to fork tube deflection. Will not dislodge during pressure washing