Sram: Accurate, reliable power measurement is practically a requirement these days, and the Apex AXS crankarm power meter upgrade is the easiest way to get the numbers you need. With the tech hidden inside the DUB spindle, it fits almost any bike while remaining stealthy.FEATURESDUB-PWR spindle-based unit measures left side power to calculate total wattsProven Quarq reliability and accuracyLong battery life (400+ hours) to power a season of ridesUser replaceable AAA lithium batteryDUB bottom bracket adds durability and simplicityWaterproof (IPX7 waterproof to 1 meter for 30 minutes)Lightweight (less than 40g heavier than standard crankset) SPECIFICATIONSSpeeds: 12Crank arm length: 160mm, 165mm, 170mm, 172.5mm, 175mmBB Compatibility: All SRAM Road WIDE DUB BBs, except AiChainring Size: No ringsBolt Circle Diameter (BCD): Direct Mount (DM)Chainline: n/aBB Spindle Interface: DUBChainring material: No ringsGuard: No GuardCrank arm material: AluminumColor (Crank arm): BlackPower Meter Type: SpindleHub Spacing Compatibility: n/a