Pro-level carbon arms with M30 Thru (30mm) alloy spindle with Gravel chainline spacing for 1x or 2x- Direct Mount 3-bolt for 1x chainring options use PX207*- For Praxis 2x chainring options, use Levatime II PX2115 or PX2116- Works with 10-12sp Shimano GRX drivetrains and SRAM "Wide" applications- Q factor of 150mm- Weight without BB and rings: 324g (172.5mm arms only)- Aftermarket 3-bolt power meter spider options available from numerous brands