The 104 BCD chainring was Wolf Tooth’s first product ever and it is the most common bolt pattern on double and triple cranksets. Wolf Tooth’s patented Drop-Stop tooth design is the best available anywhere. Compatibility: - These rings fit any 104 BCD crankset - 30 tooth rings require chainring bolts that are 7-10mm long. All other sizes require single ring specific bolts that are ~6mm long. - 30t x 104BCD ring is the only QUARQ power meter compatible 30t ring available! - For 1x9, 1x10, ,1x11 and 1x12 drivetrains (including SRAM Eagle) - Compatible with all 10, 11, and 12 speed chains (Including SRAM Eagle) - If using a 9 speed drivetrain use a 10 speed chain (shifts and works well on a 9 speed drivetrain and fits the ring tighter for better chain retention).