Sram: SHIFT REALITY Occupying a new realm in shifting performance, the redesigned XX1 Eagle™ derailleur gives no-compromise racers and dream-bike builders a true top-tier option. The crisp, precise XX1™ shifting feel athletes rely on now features an updated cage geometry for improved chain management. Occupying its rightful place at the top of the Eagle™ ecosystem, the XX1 Eagle™ rear derailleur makes full use of the new 10-52t cassettes and is backwards compatible to also work with the 10-50t.FEATURESUpdated cage geometry provides better chain retention and crisper shifting.Comes in XX1 Eagle™ master colorway as part of Eagle™ Colorsystem – to go with all cassette and chain color options - Black, Gold, Rainbow, HardChrome and all-new Copper.Backwards compatible, works with 10-50t and new 10-52t cassettes. SPECIFICATIONSSpeed (RD): 12sCable pull ratio: X-actuationCage (RD): n/aMax tooth: 52Color (RD): LunarPulley bearings material: n/aCage material (RD): n/a