SRAM Force D2 AXS Wide Left Crank Arm Power Meter Spindle Measure Your Power Power measurement is a crucial part of training, so SRAM made it as easy as possible to upgrade your Force AXS ride with Quarq technology. DUB-PWR takes the legendary reliability and accuracy of Quarq technology and inserts it into the crank spindle for clean integration that fits more bikes than ever. It's invisible technology that adds minimal weight and will help you get to the finish line faster. Features DUB-PWR spindle-based unit measures the left side power to calculate the total watts Proven Quarq reliability and accuracy Long battery life (400+ hours) to power a season of rides Right crank arm, bottom bracket, spider, and chainrings NOT included SPECIFICATIONSSpeeds12-Speed BB Compatibility DUBChain Ring-Crank Arm Length165, 167. 5, 170, 172. 5, 175mm BB Spindle Interface DUBChainring Material-Bolt Center Diameter (BCD)-Crank Arm Material Carbon Chainline-Bottom Bracket Included No Intended Use Road, Gravel Weight N/A | Sram | Force D2 Axs Wide Left Crank Arm Power Meter Spindle 167. 5Mm