SRAM, Rival PM, Left Arm with Power Meter Spindle, Speed: 12/13, Spindle: 28.99mm, DUB, 172.5mm, Black, Road

• Upgrade your existing Rival E1 crankset with spindle based power • 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 • Lightweight (less than 40g heavier than standard crankset) • SRAM Model ID: PM-RIV-ASSY-E1