Campagnolo super record 12sp rear derailleurthe 12 speed campagnolo super record rear derailleur is the heart and soul of the super record 12 speed drivetrain. Super record components are designed for competitions and to provide the optimum performance required to win at the top level. This new model still provides professional racers with the certainty of fast and exceptionally accurate shifting, even under load. However, you don't have to be a professional to take advantage of campagnolo's best performance features, the significant increase in shifting will be noticeable to any road cyclist.more efficient, better power transfer, smoother shiftingthe revised shape of the external components of the super record 12 speed rear derailleur allows it to move efficiently to give maximum performance at any angle across any cassette ratio. The design of the cage keeps the chain closer to the cassette to ensure better power transfer, a more positive drive, whilst perfectly following the curve of the cassette sprockets. This better chain sprocket interface also gives greater durability of components and is silent during use.features  ultra light main derailleur body  stiffer, less weight  optimised trajectory curve, improved shifting  close contact with each sprocket  3d embrace technology  inner mechanism embraces more teeth per sprocket  greater shifting retention and efficiency  unique 72.5mm cage, one size fits all 11 29 and 11 32t cassettes  larger 12 tooth pulley design, greater contact and cassette versatility  increased adjustability, durability and rider safety  massive performance increase and just 3 grams difference, compared to the previous  model  weight 181gbuy campagnolo components from chain reaction cycles, the world's largest online bike store.