Carbon-Ti X-MonoSync Ti, ultralight monoring with synchronized teeth, CNC made, compatible with 10-11-12 speed drivetrain. The "narrow wide" synchronized teeth allows it to work even without the chain guide. The maximum reliability is guaranteed only with rear derailleurs with clutch as SRAM XX1, X01, X1, GX, X0, X9 Type 2 or Shimano Shadow Plus. Grade 5 Titanium assure a three time longer lasting than aluminum chainrings. Available in 30T (33 gr.) - 32T (35 gr.) - 34T (42 gr.) - 36T (51 gr.), compatible with cranks with 4 holes 104 mm BCD spider (like Powermeter SRM and Quarq). 100% Made in Italy.