2-speed, DUB, without bottom bracket, 12-speed compatible, hollow carbon crank arms, direct mount aluminum chainring, 45 mm chainline, Bluetooth and ANT+ wireless technology, LED indicator light for readiness, reset, and low battery, Accuracy: +/- 1.5%, dual-sided measurement, tool-free battery replacement (CR2032) Number of chainrings 2 Primary color black Large chainring 48 T. Small chainring 35 T. Chainline 45.0 mm Crank arm length 167.50 mm Secondary color grey System compatibility 12-speed Bottom bracket DUB Crankset variation