Shimano's Dura-Ace Hollowtech II Crankset has always set the benchmark in strength-to-weight ratios, which is why it's proven itself at the highest echelon of competition. It's made of cold-forged and CNC-machined aluminum and has hollow crankarms and a hollow large chainring. Both chainrings also feature a new tooth design. The result is legendary stiffness for awesome power transfer and precision shifting you'll love. Plus, the Dura-Ace crankset is also lighter than many carbon models.