Campagnolo Super Record 12-Speed Rear Derailleur. The Campagnolo Super Record 12-Speed Rear Derailleur is made from premium materials and has been updated to provide the very best in shifting performance. Built from technopolymer and reinforced with carbon fiber, this derailleur uses new pulley wheels that improve shifting and a larger 12 tooth design that improves chain efficiency. Additionally, it uses 3D-Embrace technology which changes the position of the upper pulley wheel. This means there is more chain wrap on each sprocket in your cassette which helps improve the reliability and speed of each shift. It is available in one cage length that accepts 11-29T, 11-32T and 11-34T cassettes. Additional chain wrap on every sprocket improves the speed and reliability of each shift. One to Rule Them All. This derailleur can accept any of the Super Record 12-speed cassettes. This makes it easy to swap between cassettes based on your terrain. Compatible with most frames and Campagnolo Super Record and Record 12-speed drivetrains. Expert advice and customer service in case you need any help. At Power Meter City, we focus on power meters and related accessories and components. Our focus on these products means we can offer you the best possible selection, advice and service. We have been in business since 2016 and are based in southern California. We are an authorized dealer of every product we sell.