SRAM crank-ster "eagle axs transmission" spider pm eagle axs tr. 8 screws

- axs™ enabled for easy monitoring and firmware upgrades - 8-bolt - bluetooth low energy and ant+ compatible - power readings are accurate within +/-1.5% and aren't affected by climate conditions during a ride - power balance measures left and right legs separately - uses a common cr2032 battery that last for 200 riding hours and changes without tools