The Sram Red Rear Derailleur provides precise and quick shifting as well as a silent operation for your practices of road cycling. It is compatible with 24 and 32 teeth and 11 speeds. This bike rear derailleur is made of carbon and ceramic pulley bearings. It features Exact Actuation technology that favors precision, speed, and silent operation. It includes a new AeroGlide toothed pulley design that provides cushioning, less noise, and efficient driving.The new SRAM RED® Rear Derailleur has been designed to deliver the performance advantage you´ve come to expect from SRAM.The derailleur is designed with our Exact Actuation® technology for precise, efficient shifting.we´ve paid rapt attention to the finer details, like adding a hollow titanium anchor bolt and even refining tooth geometry of the jockey wheel.The result is that the chain runs through the RED Rear Derailleur smoother and quieter than ever before.Features:- Exact Actuation® shifting provides fast, accurate shifts- More clearance with 28t cassettes thanks to longer B-knuckle- New silent shifting with optimized AeroGlide lower pulley, ceramic bearings- New spring-fixed barrel adjuster- New chain pulley cage adds precise chain management- Titanium pinch bolt keeps a low profile while minimizing weightSpecifications:- Speeds:10- Material:Carbon cages, Carbon inner links, Aero designed titanium hardware- Weight:145gTechnology:AeroGlide Pulleys®:New tooth pulley design with a sound damping effect for a super efficient and silent ride experience.Bottom and top pulleys benefit from this feature.EXACT ACTUATION®:When we launched our road technology from scratch we reapplied our MTB proven SRAM 1:1 actuation ratio (shifter cable travel :derailleur movement) for 10 speed rear shifting.EA helps to simplify/stabilize the uneasy act of balancing rear derailleur hanger design, tight cog spacing and exact cable tension.The result:the easiest index shifting system to set up and it stays that way.For 2x10V systems.- Compatible with cassettes 11-42T.