Pro-level carbon arms with M30 Thru (30mm) alloy spindle- Cold forged, proprietary LevaTime II X-rings (104/160BCD) with steel chainring bolts- *M30 Thru BB sold separately, use PX9019 for English 68/73mm, PX9023 for BB30/PF30 or PX9022 for BB86 and PX9024 for T47 external- BB tool sold separately, use PX8980/8981- Direct Mount 3-bolt for 1x chainring conversion is possible- For additional Praxis 2x chainring options, use PX211*- Works with 10/11/12sp drivetrains, but not compatible with Shimano GRX front derailleurs- Q factor of 147mm- Weight without BB: 570g (172.5mm with 50/34t)