SRAM X-SYNC 2 12 Speed 104 BCD Chainring - 104 BCD - Round - Black - 34TThe radical look and feel of X SYNC 2 Eagle chainrings is a direct result of SRAM drivetrain engineers studying the performance and wear characteristics of thousands of X SYNC chainrings. Longer, positive rake tooth shape has been designed to work perfectly with Eagle chains to increase chain retention and overall pedalling efficiency, while decreasing friction, noise and wear. Can be used with Eagle 12 speed or SRAM 11 speed chains Chainring BCD: 104