Sram replacement X-Sync chainrings for the Apex-1 crankset with asymetrical 110mm bolt pattern - will not work with standard 110mm 4 bolt applications X-Sync� tall, square tooth design provides maximum chain control Sharp, narrow tooth profile and rounded chamfer edges help manage a deflected chain Mud-clearing recesses 110mm 4-bolt Asym 44T Alloy Black 11sp Narrow/Wide