Campagnolo B010-SM Croce D’Aune Rear Derailleur with innovative Twin-Axle-Sxstem.
“TWIN-AXLE System” of the CROCE D’AUNE derailleur is a new break-through in derailleur technology and is destined to set new standards for competition derailleurs. In races like the Giro d’ltalia and Tour de France where steep mountain roads torture both man and machine it is extremely important for the derailleur to perform flawlessly because one missed shift or slipped chain can be the difference between winning and loosing.” (1988 Campagnolo catalog)