Wolf Tooth Components WolfCage Combo Pack: Includes 49T Cog, 18T Cog, and Derailleur Cage, Blue

The GC 49 cassette extender cog allow you to modify your 11 speed Shimano 11-42T cassette to create an ultra-wide range 11T-49T cassette. Includes 18T cassette cog for optimal gearing in the smaller cogs as well as WolfCage adaptor and derailleur pulley. GC49 features 7 shift gates for faster shifting.* Shimano rear derailleurs require the use of the WolfCage with a GC49* Compatible with Shimano 11-40 and 11-42 11-speed cassettes* WolfCage fits XT-8000 GS Cage