Product Info Upgrade Wide Rival D1 cranksets to power meter cranksets. Replaces non-drive crank arm and spindle. Uses existing drive side arm and chainrings. DUB bottom bracket adds durability and simplicity DUB-PWR spindle-based unit measures left side power to calculate total watts Long battery life to power a season of rides User replaceable AAA battery SRAM Model ID: PM-RIV-ASSY-D1