Sram`s newly updated lightweight aluminum crankarms paired with a spindle based powermeterSpindle-based unit measures left side power to calculate total wattsX-Sync wide-tooth, narrow-tooth chainring technology provides maximum chain controlWide chainline for compatibility with Full Mount rear derailleursLong battery life (400+ hours) to power a season of ridesLightweight (less than 40g heavier than standard crankset)User replaceable AAA lithium battery165x42DUBBLKDirect Mount1x12/13spUPC/EAN/GTIN: 710845916076