Campagnolo chorusathena 11 speed chain the new 55mm thickness has been combined with new materials and a special anti friction treatment which permits outstanding fluidity we have reduced the width of the chain to 55mm with the new spacing and a new material has been envisaged for the outer links the pins are hollow inside to reduce the weight while maintaining strength it is necessary to use tool ut cn300 to fit it the ni ptfe treatment ensures smoothness and long life the ultra link f