The Shimano Dura-Ace 9200 Power Crankset is an elite setup that is very lightweight, stiff, and accurate. This user-friendly and accurate power meter has been designed to offer the most reliable data possible. It is accurate to within 1.5% and offers dual sided readings. This allows you to determine if there is a discrepancy in power per side while also providing an overall accurate measurement. A zero offset calibration is easy to process while maintaining over 300 hours of ride time with a waterproof battery. This crank works in perfect synergy with your Shimano 12-speed groupset. There are multiple options for crank arm sizes, so everyone can find their perfect fit. It utilizes Bluetooth and ANT+ connectivity, so using and recording workouts is easier than ever. The Shimano Dura-Ace 9200 Power Crankset features an elite combination of low weight, high, speed, and useful data collection. With this crankset, every workout results in progress. SPECIFICATIONS Weight 738 grams Material aluminum (inner ring); anodized finish; steel (crank axle) Battery Life 300 hours Compatible Chain CN-M9100