Accurate reliable power measurement is practically a requirement these days and the Apex AXS crankarm power meter upgrade is the easiest way to get precise power numbers. With the tech hidden inside the DUB spindle it fits almost any bike while remaining stealthy. DUB-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 ridesWaterproof (IPX7 waterproof to 1 meter for 30 minutes)DUB bottom bracket (Sold separately) adds durability and simplicityRight crank arm bottom bracket spider and chainrings NOT included