This is a standard issue 52T Record replacement ring for all 10 speed Record cranksets - will work with 2004 and newer Chorus cranks as well. Since the ring is a 5-bolt, 4arm design, it will only work with these hidden bolt assembly cranksets. The ring is cut and polished to Record standards - not AFT treated. UD/Ultra Drive teeth profiling for 10 speed drivetrains only. Campagnolo part FC-RE752.