From the manufacturer's official website:

All Campagnolo components are part of a unique integrated project. Every component is designed and realized to interact at one with the remaining components. The objective is to provide better-quality performance. Campagnolo cables are no exception. On the contrary, precisely because these provide the link between one component and another, the cables must be designed to interface solely with the components they connect.

Campagnolo cables employ stainless steel inner wires and friction-resistant housings that are lubricated with special grease. Laboratory testing has shown that this solution provides unparalleled smoothness. Campagnolo cables maintain a constant friction value of 20-22 N at the most critical point, i.e. when the cable is actuated. A truly incredible value when one considers that some systems produced by other manufacturers exhibit values in the range of 130-140 N.

For more information, please visit this product's webpage.