Campagnolo Super Record WRL 12-Speed Rear Derailleur. The Campagnolo Super Record WRL 12-Speed Rear Derailleur uses the latest technologies to provide you with the best shifting performance available. This derailleur is built from aluminum and carbon fiber which allows it to shift consistently while still being lightweight. In addition, it knows what cassette cog it is in which means it can shift precisely every time. It also features the Campagnolo UnLock System which allows you to manually move the derailleur into your preferred gear if you ever run out of battery life. The Super Record WRL rear derailleur is completely wireless which makes it easy to set up and install. The battery level can be monitored on the LEDs or in the MyCampy3.0 app. This derailleur is available in one cage length that accepts 10-25T, 10-27T and 10-29T cassettes so you can have the gear range best for your riding. This derailleur uses a rechargeable battery which makes it fully wireless for easy setup and install. In the rare case that you run out of battery mid-ride, you can manually move the derailleur in your desired gear. Compatible with most frames and Campagnolo Super 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.