Shimano 105 FC-5600 Double Chainset 53 / 39 Tooth Chainset - 170mm Arm - SilverShimano 105 FC 5600 Double Chainset 53 39 Tooth Chainset 170mm Arm Silver Shimano 105 is a by product of our premier engineering range but has its own unique identity, offering a greatly enhanced and sleek design that's backed by a high performance. The Shimano 105 design concept of "smooth, Round and Natural" is consistently demonstrated in every component, giving its user a sense of satisfaction and pleasure. The Hollowtech II crank and bottom