We cut grams out of our aluminum crankarms, but didn’t cut corners on power measurement. Our light and accurate spindle-based power unit nestles into our striking redesigned arms to give you the data you need, and our newest direct mount chainrings are light and stiff while looking good. 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 AAA lithium 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) SRAM X-SYNC wide-tooth, narrow-tooth chainring technology provides maximum chain control Wide chainline for compatibility with Full Mount rear derailleurs SPECS: Speeds: 12, 13 BB Compatibility: All SRAM Road DUB BBs Chainring Size: 42T Crank Arm Length: 160mm, 165mm, 170mm, 172.5mm, 175mm Chainline: 47.5mm BB Spindle Interface: DUB Chainring Material: Aluminum Guard: No Guard Bolt Circle Diameter (BCD): Direct Mount (DM) Crank Arm Material: Aluminum Color (Crank Arm): Black Power Meter: Yes Power Meter Type: Spindle Bottom Bracket Technology: n/a