Rival power meter unit is entirely contained within the DUB spindle for ceffortless integration with any bike - Just install, pair, and rideSpindle-based unit measures left side power to calculate total wattsLong battery life (400+ hours) to power a season of ridesDUB bottom bracket adds durability and simplicityIPX7 waterproof to 1 meter for 30 minsUser replaceable lithium AAA battery172.5mmDUBBLKDirect MountUPC/EAN/GTIN: 710845915444