The choice of SRAM's top professionals, their lightest, stiffest, and most accurate integrated power meter and chainring combo just got lighter with a new carbon crankarm construction. The SRAM power meter is accurate to +/-1.5% and isn't affected by temperature changes, and the consistent 13-tooth gap on the rings ensures fast and reliable shifting. SRAM's integrated rings are also incredibly long-lasting. Plus they're offering more crankarm lengths than ever before to ensure this crank works for you. Power meter is fully integrated into the chainring for lighter weight and greater accuracy. Power readings are accurate within +/-1.5% and aren't affected by climate conditions during a ride. Measures right and left leg power balance. One-piece 2x chainring results in a lighter weight, stiffer, more durable crankset. 29g lighter than the previous generation. X-Range gearing technology gives you more range and a smoother gear progression, so you're always in the right gear. Designed to deliver crisp and accurate front shifts. Ultra-light hollow carbon fiber crankarms. DUB bottom bracket adds durability and simplicity (Sold separately). 45mm Chainline. Item Specifications: Rings: 50/37, Number of Chainrings: Double, Drivetrain Speeds: 12, Chainring BCD: Direct Mount SRAM, Chainline/Hub Compatibility: 130 Hubs, Chainline/Hub Compatibility: 135/142 Road Disc Hubs