Campagnolo Record Rear Derailleur – 12 Speed, Medium Cage, Carbon. The Record 12-Speed rear derailleur has an innovative shape that envelopes the cassette better, thanks to 3D Embrace technology, creating a double effect: allowing the chain to maintain optimum traction at all times, thus increasing the speed, power and precision of shifting. To increase strength while keeping weight to a minimum. 12-tooth pulley wheels for smoother chain movement. Rear Der/Shifter Compatibility: Campy 12-Speed Chorus/Record/Super Record 2019+. Rear Derailleur Mount Type: 10×1 Standard. Chain Wrap Capacity (teeth): 37. This listing is currently undergoing maintenance, we apologise for any inconvenience caused.