The 5.5mm width of the Campagnolo's 11 speed Ultra Shift chains makes them the quietest and quickest shifting chains they've ever made. It's also their toughest-ever chain design thanks to the retention force inherent to its Ultra Link technology. The benefits of the Chorus, Record, or Super Record 11 speed chain are all byproducts of its narrowness, but this narrowness comes with one implication: The installation process requires an unprecedented degree of precision. Which is why Campagnolo requires you to use their UT-CN300 chain tool for installation. By using the UT-CN300, the chain is perfectly stabilized, allowing you to install the Ultra Link with the exacting care the design demands. In the tradition of Campagnolo tools of yore (we're thinking of their facing and chasing tools...), the price tag might raise an eyebrow, but Campagnolo 11 speed is utterly pro quality equipment, which demands a small investment in this one pro quality tool.