SRAM RED E1 AXS Aero Power Meter Chainring Kit When you need the absolute best from your training data the pro-proven accuracy and reliability of the RED AXS power meter is the way to go. Integrated into the chainring itself it's light stiff and aero accurate to +/-1. 5% even as weather conditions change and retains chains even when you hit rough stuff. Features AXS enabled for easy monitoring and firmware upgrades Single-ring drivetrain simplifies functionality Fully integrated power meter into a direct mount aero chainring Power readings are accurate within +/-1. 5% and aren't affected by climate conditions during a ride Ant USB type power meter type X-Sync wide-tooth narrow-tooth chainring technology provides maximum chain control SPECIFICATIONSMaterial Aluminum Round or Oval Round Power Meter Yes Direct Mount Type Direct Mount SRAM 8-Bolt Drivetrain Speeds12 , 13Defined Color Black Offset6. 5 | Sram | Red E1 Axs Aero Power Meter Chainring Kit 44T | Aluminum