SRAM X-Sync 2 Eagle Direct Mount Chainring - 30 Tooth 3mm Boost Offset 12-Speed Polar GreySRAM X Sync 2 Eagle Direct Mount Chainring 30 Tooth 3mm Boost Offset 12 Speed Polar Grey. Intense study of chain and chainring wear patterns led to the radical tooth profile that lasts longer runs quieter and further improves chain retention. Fully CNC Aluminum ring construction Eagle technology provides an expanded optimum gear range for 1x drivetrains X SYNC 2 chainring design increases chain retention wear life and reduces friction and noise