SRAM X4 Rear Derailleur - 7,8,9 Speed, Long Cage, Black
The SRAM X.4 line-up sets the standard for recreational level shifting. The X.4 has an intelligent blend of performance and value for MTB or pavement. Compatible with 7-, 8-, and 9-speed systems, 1:1 shifter-to-derailleur actuation ratio for precise light-action indexing. Must be used with ESP shifters.