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 watts - Proven reliability and accuracy - Long battery life (400+ hours) to power a season of rides - User replaceable AAA lithium battery - DUB bottom bracket adds durability and simplicity - Waterproof (IPX7 waterproof to 1 meter for 30 minutes) - Lightweight (less than 40g heavier than standard crankset)