Sram Apex 1 Rear Derailleur 11 Speed Long CageThe Sram Apex 1 Rear Derailleur provides the gear range and the shifting simplicity to let you simply go where you want. The Apex 1 rear derailleur makes that gearing choice a reality with clean, crisp shifts, thanks to SRAM's X-HORIZON geometry and our ROLLER BEARING CLUTCH. Just go with the Apex 1, it will get you there. The Cage Lock Technology makes wheel removal and chain installation quick and simple. Works on 11 speed cassettes with a 42 tooth max.710845783203