Invisible technology that will help you get to the finish line faster? Yes please. Our Rival power meter unit is entirely contained within the DUB spindle for effortless integration with any bike. Just install, pair, and ride. FEATURES: Spindle-based unit measures left side power to calculate total watts Long battery life (400+ hours) to power a season of rides User replaceable lithium AAA battery DUB bottom bracket adds durability and simplicity Waterproof (IPX7 waterproof to 1 meter for 30 mins) Lightweight (less than 40g heavier than standard crankset) SPECS: Speeds: 12/13 Crank Arm Length: 160mm, 165mm, 170mm, 172.5mm, 175mm BB Compatibility: All SRAM Road DUB BBs, All SRAM Road WIDE DUB BBs Chainring Size: n/a Bolt Circle Diameter (BCD): Direct Mount (DM) Chainline: 44.7mm, 47.5mm BB Spindle Interface: DUB Chainring Material: n/a Guard: n/a Crank Arm Material: Aluminum Color (Crank Arm): Black Power Meter Type: Spindle Hub Spacing Compatibility: n/a Chainring Offset: n/a